Tips and Tricks, Suggested Solutions

The following section describes relevant learning experiences gained by Labdooers around the world who (like you) are helping to sanitize laptops and make them ready for needy schools. It will teach you tips and tricks that will be very handy when sanitizing your laptops. If you are not able to find a solution to your problem in this section, please ask your questions to the Labdoo QA team and another Labdooer there will provide an answer for you.

Delete All Data on Hard Disk


We want to ensure all data stored in every donated computer is properly erased before installing the new operating system. Therefore learning how to properly erase the hard drive is the first step in the laptop sanitation process.

You have 2 options to completely wipe out all previously stored information in the computer (user information as well as all the previously installed softwares and operating system)

Method1: Using Lubuntu disk

  1. Boot your laptop with your Lubuntu disk (see the simple sanitation guide to learn how to create a Lubuntu disk)
  2. On the Lubuntu menu, select the option 'Try Lubuntu'. This will start Lubuntu on the laptop.
  3. Once booted, press at the same time the keys ALT+CTRL+F3. This will take you to a terminal console.
  4. In the terminal console, type the following command to ensure that the shred application is available:

    apt-get install coreutils

    (you need to have your laptop connected to the Internet for the above command to succeed)

  5. Now type the next command:

    sudo shred /dev/sda -f -v --iterations=2

    If this command does not work, you can try with 'hda' instead of 'sda', like this: sudo shred /dev/hda -f -v --iterations=2.

  6. Now wait for about an hour or so for the previous command to complete. At the end of this process, the laptop hard drive will have all of its previous data fully removed. You can now press ALT+CTRL+F7 to return back to the Lubuntu initial screen and turn off the laptop.

Method 2: Using Parted Magic or Labtix.iso

  1. Boot your laptop with Parted Magic or Labtix disk (see Advanced Method(Without Network) to learn how to create a Parted Magic disk)

    Or you can boot your laptop with the Labtix disk (see Preparation for the Fast Installation Methods to learn how to create a Labtix disk)

  2. Once booted, click on the bottom ROXT Terminal (xterm icon on the lower right) This will take you to a terminal console.

  3. In the terminal console, type the following command to ensure that the shred application is available:
    sudo shred /dev/sda -f -v --iterations=2

    If this command does not work, you can try with 'hda' instead of 'sda', like this: sudo shred /dev/hda -f -v --iterations=2.

  4. Now wait for about an hour or so for the previous command to complete. At the end of this process, the laptop hard drive will have all of its previous data fully removed. You can now shutdown the laptop from Parted Magic window.

Adapt Bluetooth's Name (Optional)

If you sanitized your laptop via the advanced method, then due to the cloning process, the name of the laptop's bluethooth device will be identical to all clones. To assign a unique name to your device, run the following command on a terminal:

sudo hciconfig hci0 name ’labdoo-XYZ-0'

Where XYZ is the Labdoo ID of the laptop.

Add a 2nd Disk Drive

If the installed hard disk becomes too small and the computer allows the installation of a 2nd disk, you can configure such 2nd disk to mount automatically during booting time. To do so you have to:

  • Press ALT+CTRL+T at the same time to start a terminal, and type the following command to initiate the file manager in superuser mode: sudo pcmanfm & (enter).
  • Navigate to the folder /mnt and create inside it a new folder with the name of the 2nd disk.
  • Get the UUID (ID of the disk-drive) of the 2nd disk by typing the command sudo blkid, search for your 2nd drive in the list and write down its UUID.
  • Type the following command to edit the fstab file: sudo nano /etc/fstab [Enter]
  • Add at the end of the fstab file a new line as follows (in one single line):
    UUID=[add here the UUID of the 2nd disk you wrote down above]
    /mnt/[add here the name of the 2nd disk folder you created above] auto defaults 0 0

    (Make sure to leave a space character between each entry)
    Leave the file editor by pressing CTRL+X then Y (to save) and [Enter].
  • Optionally, to allow access for all users to your 2nd disk do as follows: Open your file manager in superuser mode again sudo pcmanfm &, go to your 2nd disk folder and right click on it with your mouse. Under properties, select "Access rights for others", check the "Allow create or delete new files / folders", and then "Apply to all folders".

Re-boot your computer. The new disk should be automatically mounted.

Add a Local Printer as Network Printer

If you have a printer directly connected to your Labdoo computer (via USB or a Centronics cable), you can share access to the printer from other computers via a local network. To do so you need to use CUPS (Common Unix Printing System) as follows.

Configuring the Labdoo computer attached to the printer:

  • Open the web browser and type the URL address http://localhost:631
  • On the admin page http://localhost:631/admin/ select “Share printers connected to this system”.
  • Select under ”Printers” the connected printer.
  • Click on the menu “Administration” and on “Printer”.
  • Leave “Actual connection” unchanged → Proceed → select “Allow access to this printer / share”.
  • Optional: add a name for the place of installation → Proceed → Change settings.

Showing the printer on other Labdoo computers connected via the network:

  • Open the web browser and type the URL address http://localhost:631/admin
  • Select the option “Show printers shared by other systems” → Change settings.

After this you should see the printer in the menu “Printer". Maybe you have to wait a little bit before the printer is shown or re-load the page http://localhost:631/admin/.

Configuring the Bios

How to change the booting order of a laptop from the bios

BIOS (Basic Input Output Subsystem) is a programmable chip that controls how information is passed to various devices in the computer system. A typical method to access the BIOS settings screen is to press ESC, F1, F2, F8 or F10 right after you start your computer.

BIOS settings allow you to run a boot sequence from a hard drive, a CD-ROM drive, the network, or an external device. You may configure the order that your computer searches these physical devices for the boot sequence.

The first device in the order list has the first boot priority. To install the Labdoo software you will need to ensure the CD-ROM, the USB or the network (depending on which method you use to install the software) are given the highest booting priority.

Note: in the case of a USB installation, before you set boot priority for the USB device, plug the device into a USB port to ensure the BIOS will be able to detect it.

To specify the boot sequence:

  1. Start the computer and press ESC, F1, F2, F8 or F10 (depending on the BIOS manufacturer, try them all if needed) multiple times during the initial startup screen. A menu may appear.
  2. Choose to enter BIOS setup. The BIOS setup utility page appears.
  3. Use the arrow keys to select the BOOT tab. System devices appear in order of priority.
  4. To give the CD/DVD, the USB or the Network the highest boot sequence priority, move such device to the first position in the list.
  5. Save and exit the BIOS setup utility.
  6. The computer will restart and will initiate its booting process by looking first at the device you gave the highest priority, allowing you to install the Labdoo software.

Figure. Illustration of the BIOS boot menu where you can change the booting order.

Troubleshooting potential issues with the bios.

In some rare cases the BIOS could be reset during the process of deleting the hard drive information from the system, or some times older laptops do not support internal and/or external USB keyboards during the booting process. It might happen that you are not able to use the arrow keys (up, down, right, left) to configure the BIOS. In such cases the USB control (and sometimes the internal keyboard) was deactivated. A possible solution is to connect an external PS/2 or USB keyboard, and continue to install or adjust the BIOS.

DKMS (Automatically Driver Updates)

Dynamic Kernel Module Support (DKMS) is a program/framework that enables generating Linux kernel modules whose sources generally reside outside the kernel source tree. The concept is to have DKMS modules automatically rebuilt when a new kernel is installed.

An essential feature of DKMS is that it automatically recompiles all DKMS modules if a new kernel version is installed. This allows drivers and devices outside of the mainline kernel to continue working after a Linux kernel upgrade.

To install DKMS, do as follows:

- Open a terminal by pressing at the same time the keys ALT + CTRL T
- Type in the following command:
sudo apt-get install build-essential dkms [Enter] + [Password] + [Enter]

Note: DKMS is already installed if you cloned a laptop using the advanced method or if you used the

Firefox shows black bar in URL


In combination with an Intel graphic card Firefox shows sometimes in the URL line a black bar. There is nor solution for that, just a workaround:

  • Type in the adress line (URL) of Firefox about:config
  • Acknowledge that you will be careful
  • Type in the search gfx.xrender.enabled
  • When shown click with the right mouse button on true and click on toggle, so that the value is switched to false.

If there is nor entry gfx.xrender.enabled (double check that you did not mistype!):

  • click in the white space of the search entry
  • Select New in the dialogue window
  • In the next windows select boolean
  • In 3rd window select false and confirm with ok

Restart Firefox

Check for Disk Errors with GSMART

To check whether a disk has potentially any errors, you can use the Lubuntu tool GSMART. Since it is not installed by default, it must be installed via the Ubuntu Software Center. Select GSMART and install it. After installation, start it and initiate a check. This software includes a quick check (about 10-20 minutes) or a detailed check (about 30 - 60 minutes).

In case you want to check multiple disks, you can use a hard disk adapter. The adapter should support IDE and/or SATA via a USB connection to your laptop.

Installation of Restricted Codecs

Please notice that the usage of restricted codecs might depend on local laws. It might be illegal in some countries to install and use certain codecs (commercial/proprietary third-party packages) and multimedia extensions. Check your local regulations first prior to proceeding with the installation of the following software.

As in all software for Ubuntu, there are two ways to do the installation: via the Ubuntu Sofware Center or via the command line.

The installation via the Ubuntu Software Center is as follows. Open the Ubuntu Software Center (or the Synaptic Package Manager) and search for "restricted codecs". Select the package found and click on install. During the installation you will need to accept an EULA license agreement. To have full support to watch DVDs you must also install libdvdcss2 and non-free-codecs from the Medibuntu Repository. Please notice that in Europe these repositories are not allowed to be used. Further information can be read here:

The same installation can be done via the command line through the following steps. Open a terminal by pressing at the same time the keys ALT+CTRL+T. Then type the following commands:

sudo apt-get install ubuntu-restricted-extras -y (Enter)
sudo apt-get install non-free-codecs -y (Enter)
sudo apt-get install curl -y (Enter)
curl | (Enter)
sudo apt-key add -echo "deb ./" | (Enter)
sudo tee /etc/apt/sources.list.d/libdvdcss.list (Enter)
sudo apt-get update (Enter)

Enhanced Intel Graphical Interface

If you have a computer with an Intel graphical interface, there is a cool free tool by Intel Graphics for Linux that you can install, check it out:

To install it do as follows:

  • Open Firefox and go to
  • Depending on the Ubuntu release (version 32 or 64 bits) download the matching software and install it.
  • Once installed, find the newly installed application and run it. It will guide you through the process of configuring your system for Intel Graphics. Once done, you will need to restart your computer to load the new configuration.

Kernel Panic Caused by Defective in Memory/RAM

If the computer crashes often during the boot process, there is a possibility that it is because of a defective memory (RAM) module. (There could be other reasons too naturally).

To check if the RAM module is working properly (memory modules) do as follows:

  • Boot the system and press SHIFT at the same time.
  • The GRUB menu will show up. Click on Memtest86 (memory test).
  • The system will perform a memory test. At the end of this test, the defective parts (if any) will be listed and marked in red.

Hint: To know exactly which memory module is defective, you can remove all memory modules and check each of them individually by running the above test.

Wired LAN Interface is Not Working

In some systems, the wired (cable) LAN interface may not be recognized. The symptom is that the interface shows up when you click on the network manager icon but it shows as deactivated. To get it to work, try the following:

  • Open a terminal by pressing ALT+CTRL+T and type the following command: sudo nano /etc/NetworkManager/NetworkManager.conf
  • Check and change this line: managed=falsemanaged=true
  • Save the file and restart the network manager: sudo service network-manager restart

LXDE - Create a link to folders or files

To create a symbolic link:

Using the file manager. Open file manager PCMan, click on the folder or file, press CTRL+SHIFT and click on the folder/file at the same time, then drag and move it to the desktop or the location where you want to create the symbolic link.

Using a terminal. Open a terminal by pressing ALT+CTRL+T and type:

ln -s -t [path to location where you want to create the link] [folder or file that you want to link] (Enter)

For example: ln -s -t /home/labdoo/Desktop /home/labdoo/Public/videos

More information at:

MD5 Checksums

MD5 is a common way to calculate checksums to test if a file was downloaded correctly. You can read more about MD5 here

In the folders of your unzipped Labdoo images for cloning you will find a file MD5SUM. Use these files to check if the downloaded images are healthy and not corrupted by the download process as follows.

Check that the downloaded images are correct:

  • Open a Lubuntu terminal
  • Navigate to the folder where the files are located cd ...(path) [enter]
  • Execute the commandmd5sum -c MD5SUM [enter]

Create MD5 checksums:

Open a terminal in the folder with the files and execute in a terminal
md5sum * > MD5SUM (Enter)

16.04 LTS does not boot, graphic resolution on screen low

Grub 2 (GNU GRand Unified Bootloader 2. Generation) is the tool that rules the Boot order in the Linux Machines

We try to give here some tips on the different problems you may have with it. You can find an overview under and its configuration possibilities under

We will describe here some of the possible problems you might experience when you boot (L)Ubuntu 16.04 LTS for the first time. Some laptops do not boot up properly, but instead "hang", or they can have a wrong, too low, graphic resolution, or they may go straight off at startup, or hang with a black screen. These problems can often be resolved by setting in the Grub configuration file.

If a laptop gives you too much trouble, contact a Labdoo Hub and its helpers.

Start computer using the "Recovery Mode" as follows:

  • Keep the Shift-button pressed when turning laptop on, press again after the BIOS messages shown, until the Grub menu is shown (GRUB controls the start process). You will also see the GRUB menu if power (I/O) is turned off during a start process.
  • Select "advanced options" and a Linux-Kernel and "Recovery-Start", just accept the next entries (press Enter) and log-in as labdoo user.
  • Alternatively, press the "e" key when the Grub Select menu appears. This change only applies to this boot process and does not replace the Grub2 configuration file for next boot processes (so that the configuration file needs to be modifed).

Changes in the grub2 configuration file

  • After booting and logging in, open an editor like nano , eafpad or vi. In this document, the further steps are based on the use of the nano-editor.
  • Open a terminal and type sudo nano /etc/default/grub (Enter). This will open the GRUB configuration file. If you are not familiar with the nano editor can use leafpad instead sudo leafpad /etc/default/grub (Enter)
  • After you have done the desired changes in the configuration file, save it and end editor (using nano editor by typing STRG/CTL and the letter o, then press Enter, next type STRG/CTL and x)
  • Then open a terminal and type sudo update-grub (Enter). This will finally store the changes made within the GRUB configuration.
  • Reboot computer. Hopefully the new configuration allows you to get the login screen correctly displayed


Computer does not boot or graphical resolution is wrong

If the graphical resolution is wrong (usually too low), try:

  • Edit the grub config file as described above
  • Search the line # GRUB_GFXMODE=640x480 and remove "#" at the beginning of the line (this "#" symbol disables the configuration described in that line, by removing the '#' you are now configuring a determined resolution). Change the pre-set resolution of "640x480" in the setting you need for the graphic resolution. Important: you may only use a resolution supported by your video card! You can get the possible resolution(s) as follows using the (L)Ubuntu desktop or Parted Magic:

    • (L)Ubuntu Desktop: Menu, select Preferences → Outputs → default → Resolution : will show available settings for resolution
    • Parted Magic:
      • Menu → Desktop Settings → Screen Layout Editor → Outputs : will show available settings for resolution
      • OR
      • System Profiler → Display → Resolution
  • Store the modification and end editor.
  • Then open a terminal and type sudo update-grub (Enter). This will finally store the changes made within the GRUB configuration.

Having made these changes you have a good chance to start your laptops using (L)Ubuntu 16.04 LTS, showing a good resolution on screen.

Computer goes to sleep when booting

The option acpi=off can help if the computer switches to sleep mode during the boot process.
More information can be found under (link is external)

Computer hangs at startup

Try he option pci=nomsi, more information under

Computer takes a long time to boot up and even after the login to the display of the desktop

Try to configure video=insert SVIDEO-1:d; If this works, in the grub confguration file, the line should look likeGRUB_CMDLINE_LINUX_DEFAULT="quiet splash video=SVIDEO-1:d", more information under

Install Jitsi Meet


Jitsi Icon

Jitsi Meet is a open source tool for video conferencing, e.g. Since Jitsi is currently being requested more often for home schooling, we are describing here how it can be installed on Labdoo computers by yourself. Jitsi is free software, but not listed in the Ubuntu repositories ("app stores"), at least not by the beginning of 2021. Jitsi has been included in the DE_120 image for cloning since the beginning of 2021.

Jitsi can be used in a web browser in combination with a Jitsi plugin or by downloading Jitsi software.

We recommend to install Jitsi as "AppImage". Everything that Jitsi needs is contained in one file. Download, click, if necessary create a launcher on the desktop, done. The latest Jitsi AppImage can be downloaded here (only for 64 bit CPU).

Being logged-in as user labdoo, create a new folder jitsi in the folder /home/labdoo/Public. Here you store the Jitsi AppImage.

Use the prepared Jitsi starter / launcher: If you want, you can now create a Jitsi starter on the desktop, either manually or by going to and download from here the files Jitsi.desktop and jitsi_icon (to store a files, right-click a file in the browser → save as) and save it in /home/labdoo/Public/jitsi. Then you copy the file Jitsi.desktop to the desktop of the users labdoo and student. At the first start (launch), the operating system will ask you whether this starter is trustworthy. Confirm and all is done.

Manually create Jitsi Starter / Launcher: Right-click on the desktop → Create Launcher → Type: Application, Name: Jitsi, Command: click on Browse ..., navigate to the folder /home/labdoo/Public/jitsi, click on the file .....AppImage, open → Comment: Jitsi → OK. Repeat this for users labdoo and student, done.

In rare cases the executable bit of a downloaded AppImage is missing. If Jitsi does not start, navigate to the jitsi folder, right-click the Jitsi AppImage → Properties → Permissions → check and mark "Executable", if not already activated.

And every now and then you check whether there is a new Jitsi AppImage available on the web :)

Manually create a guest account in Ubuntu20.04

Ubuntu20.04 has some problem with Guest Session. You can create a guest account with the following procedures
1. Select "Administration->Users and Groups ->Add" , to create a new "guest" user:
Name: guest
Username: guest
2. Select the "guest" user and go to the "Advance Setting"
1. Under "Advanced" tab, deselect "Disable account" box
2. Click on "Change" Password, and select "Don't ask for password on login" box
3. Edit "/etc/lightdm/lightdm.conf " file to disable the guest session created by Ubuntu20.04 and add logout procedure for new guest account


4. Create a /home/labdoo/Public/ file as followed

if [ $USER = "guest" ]
rm -r /home/guest/*
cd /home/guest
mkdir Desktop Documents Downloads Music Pictures Public Templates Videos
chown guest *
chgrp guest *
rm -rf /home/guest/.mozilla/firefox

You can find more extense and precise information on how to create accounts and manage their permissions from the following Linux Users Tutorial

Temperature Workaround

The Temperature_Workaround lowers the maximum CPU frequency on a MacBook or laptop with an unreachable UEFI/BIOS due to a preset "Turbo" or "Boost" mode gets too hot. With some laptops you can also turn down the CPU in the BIOS, but it is simply ignored. Then this workaround will help.

With the workaround, the governor and the maximum CPU frequency are set to previously determined meaningful values ​​with systemd when booting.

The workaround is currently available as a .zip file that can be downloaded from

Please read the included README carefully!!!

With the workaround, the governor (the "controller" for the clock frequencies) and the maximum CPU clock frequency are set in such a way that the temperature remains within an acceptable range.

The workaround only makes sense if:

  • ( already under labtix from 2.07 ) a clock frequency above approx. 2500 Mhz is displayed,
  • the temperature under stress_cpu is too high,
  • There is no access to the BIOS/UEFI to turn off "Turbo Boost" or similar.

As always, it should be checked in advance whether the ventilation system is not dirty. Spent thermal paste can also cause excessive temperatures. Especially if the clock frequency is not excessive - but that is actually part of the standard procedure when the temperatures are abnormal.

The dependencies are cpupower-gui...1.0 ( included in the .zip ), Psensor, Stress ( both already included in labdoo ) and Yad ( not yet included in the Labdoo installation, but may change from the end of 2022 ).

Change keyboard layout when logging in (Boot)

The Image for Cloning "remembers" the keyboard layout of the computer, on which the image was generated. Usually Images are produced on computers having a German keyboard - sorry for that :( When you start a computer with a different keyboard layout you might have a problem to log-in properly. You are able to change the keyboard layout for each user after logging in. But that will not solve the problem. First you have to log-in and next you have to change a system setting.

Here is the layout of a German keyboard so you should be able to find the letters labdoo (our standard password to log-in). After logging in you should change the keyboard layout first and next change the keyboard system setting.

For LXDE/MATE and Log-in (Light-DM)

Having booted you are able to log-in. The computer will get the keyboard layout of the file /etc/default/keyboard. You change it as follows:

  • Open a terminal,
  • type sudo nano /etc/default/keyboard and press (Enter)
  • in the terminal window search for the line XKBLAYOUT="de"
  • change de to the keyboard layout you need e.g. en, fr etc.
  • optional: Changing the next line XKBVARIANT="" you can add a country specific keyboard layout (e.g. "ch" für eine deutsch-schweizer Tastatur de-ch or a special Spanish variant etc.)
  • Save modified file (Ctl/Strg + O (enter), close terminal by pressing Ctl/Strg + X)

Important: The keyboard layout for the users labdoo or student will not be changed by this setting. After logging in you can change the user keyboard as described here

Monitor is only showing a small part of the full screen

The installation process was successful and you are able to boot, but when logging in you are only able to see a part of the screen (usually the upper right screen corner) with a poor resolution.

This could be because in the BIOS setting not enough RAM was allocated for the screen memory, e.g. 1 MB instead of 8 MB or more. Please check the bios and increase the memory allocated for the screen memory if necessary.

Samba / Windows Server

Starting from April 2018 and with the 18.04 LTS (L)Ubuntu release, a Samba server comes pre-installed on image cloned laptops. This means that a Labdoo laptop can be used as a server to other computer clients allowing these clients to access all the educational content in the server. This is a powerful configuration as it allows many types of devices (laptops, tablets, mobile phones, etc.) to access the educational content in the server without the need to have access to the Internet or the need to replicate the educational software in many devices.

Due to the speed of the server or the network, there are limitations in the number of computer clients that can be supported by one computer server. If too many clients are connected, the performance of the data transfer will become slow. So if you have many computer clients, it may be necessary to have more than one computer server.

This page describes how you can convert a Labdoo laptop into your own computer server to provide access to other computer clients. With a few simple steps a server can be set-up, check out the next instructions on how to do that!

Install Samba server

  1. Install the package "samba" by running in a terminal sudo apt-get install samba or via the Linux package manager, e.g. synaptic.
  2. Type smbd [Enter] in a terminal to start the Samba server manually. To avoid starting this program each time manually, you can add "smbd" as a command in menu → Preferences / Settings → Personal / Personal → StartUp Applicatons / Start Programs → with "Add" → Name: Samba / command: smbd / Comment: add start up of Samba Server.. This will start the Samba server every time you reboot the system.
  3. If necessary, install additional extensions to the system's file managers to bring a better use experience. For instance you can install "caja-share" by typing in a terminal sudo apt-get install caja-share or by using the synaptic package manager (this extension is also part of the Labdoo Image since April 2018).

Set up the Shared Folders

  1. Open Caja as administrator/root by running sudo caja [Enter] in a terminal and right click on the folder you want to share. Click in the context menu "Share". Please notice that if Caja is not started as root, the menu item "Sharing" will not appear.
  2. Activate "Share this folder" and "Guest access", then enter your own "Share name".
  3. Close Caja.
  4. Alternatively for LXDE Desktop, install instead the File Manager PCManFM: Go → network → usually then the server is already recognized and displayed, otherwise Windows network → Workgroup → Server name select, usually labdoo-00000xxxx where xxxx is the Labdoo ID of the computer.
  5. Finally, don't forget that the computer must be connected to the network via LAN cable or WiFi.

Access to the server via tablet, mobile phone, laptop or PC clients

Depending on your client and operating system installed and in use (Android, iOS, Windows, Linux etc.) access to the server may be different. Below you will find some examples and tips. There are also useful programs such as file managers, browsers, pdf viewers or ebook readers on your device. Check if your file manager is able to connect to a server (not all apps are able to) or if additional extensions need to be installed.

Access to the Server Using a Client

  • In a (L)Ubuntu officially cloned Labdoo laptop comes with the file manager Caja. Either use the Menu → Places or use Caja and in the left column go to "Browse the Network" to scan and show all the servers in the network.
    • Android - open your file manager and click on "network". The network will be scanned for SMB-shares which will be shown in a file manager. If your installed file manager is not able to handle SMB, you have to install one with this ability. We recommend the file managers Ghost-Commander (to be installed using the apps store Google Play: both Ghost Commander and Ghost Commander - Samba Plugin need to be installed) or the X-plore add on.
    • iOS (Work in Progress)
    • Windows (Work in Progress)
  • To open the "Public" shared folder just double-click it. Then confirm "Connect as anonymous" to get connected.
  • For a faster experience, nearly all operating systems and file managers offer a way to bookmark favorite folders. Use it to bookmark the access to the server.

Connecting to the Server Using Ghost Commander in Android

The example Ghost Commander is similar to other file managers.

  1. Start Ghost Commander.
  2. Open "home" directory (arrow with dot right upper corner).
  3. Click on "Windows shares".
  4. In the window "Connect to Windows PC" click on "Search". No further input should be needed to connect to the server.
  5. Click on "Workgroup".
  6. Click on the name of the server you want to connect to.
  7. The shares of the server should be listed in your file manager.

To create a Bookmark Using Ghost Commander

  1. Click and hold on for about 2 seconds on the share you want to bookmark until a context menu opens.
  2. Click on the context menu "NAME_OF_THE_FOLDER as favorite".
  3. Now you will see the share at /Home (Arrow and dot upper right corner) /Favorites and have direct access, provided the SMB server is online and connected to the local network.

Note: Some file managers first store documents and pages locally before opening and displaying them. This can end up filling up the memory in your device. Cleaning up the memory can help.

Display Educational Content and Documents

  • Off-line web content: can be shown in your client's browser. Local off-line content must be stored using relative links (not absolute links).
  • pdf: to be displayed and read using a PDF viewer.
  • Office documents: It does not matter if you want to open and read Microsoft Office, LibreOffice, OpenOffice documents etc. in all these cases a viewer software app must be installed which can handle the file content.
  • Video / audio files: In this case the client must also have matching software / apps installed to watch videos or to listen to audio files.

Make Xowa Accessible from other Devices

Xowa comes with an http-server to help share Xowa wikis within a local network. Navigate to the folder /home/labdoo/Public/xowa and open a terminal (e.g. using the file manager Caja: File →open a terminal here). Run the Xowa-jar file in this folder as follows:

For 64 Bit installations: java -jar xowa_linux_64.jar --app_mode http_server [Enter]
For 32 Bit installations: java -jar xowa_linux.jar --app_mode http_server [Enter]

Don't close this terminal window, as otherwise the Xowa process will be stopped. So leave it open as long as Xowa is used by other client devices.

Some devices, operating systems and browsers can resolve the hostname into its IP address. The IP address is like the address number of a home, which controls the access to each device inside your LAN (Local Area Network).

If the IP address cannot be resolved automatically you can get it manually. From the server computer, first right mouse click on the network/WiFi symbol on the desktop → Connection Information → read IP address (often similar to Notice: The IP address will change every time, when you reboot the server (if you run DHCP for dynamic IPs in your network). It might be helpful to assign a static IP address to your server.

Read Xowa Content on any Client

The following is based on the IP address just to illustrate an example. Instead of this IP address, use your server's IP address. Open the browser of your choice on your device (tablet, mobile phone, PC) and type the address of the server:
In our example:

Related Links and References

Using a Laptop as WiFi Hotspot to provide educational data to mobile devices

If a Labdoo laptop is member of a LAN or WiFi network, it can provide data (educational content) to other devices of that network, e.g. to mobile phones or tablets. This can be done either by some network share – e.g. via samba (smb) or e.g. via a web server (e.g. Apache web server). In both cases, educational content on that laptop could be accessed by other mobile devices (mobile phones, tablets) via their web browser. This might be a reasonable use case if these mobile devices do not contain Labdoo educational content (e.g. due to having not enough disc space for this content)or no having internet connection.
In the case of a WiFi connection, we commonly assume that our laptop is connected to a WiFi router, to which all other mobile devices are connected.
laptop and wifi router

But what do we do if no WiFi router is available? If a WiFi USB-adapter or a built-in Wifi is available on it, is possible to use a laptop as hotspot and host a WiFi network. There a 2 options - use a Samba (smb) file server, which offers a Windows-compatible server (easy to start and handle). Or you can use Apache server, which is bringing a full web server to a laptop (more complex), being able to spread content and web-sites locally and world-wide (if connected to internet).
Such a setup is outline in this document.

using Samba (smb) server
laptop and wifi router

using Apache web server
laptop and wifi router

Target Group
The target groups are Labdoo schools, which do not have a running WiFi network, but need a network to provide file, content and/or Internet access to other mobile devices.
Example: The Labdoo school have tablets or smartphones, but no Labdoo content on them.

Then the school is able to use a Labdoo laptop as server and spread the educational content to mobile devices. The number of mobile devices to be provided by one laptop depends on its capacity, mainly speed of CPU, disc and WiFi connector. In our tests we found 3 - 10 devices a reasonable number of clients to be connected to one laptop.

Each Labdoo laptop comes with a preinstalled Samba server (smb). How to start the smb-server and how to connect mobile devices to it is explained here.

You will find most content on each laptop in the folder /home/labdoo/Public/wikis. Navigate in a browser of your mobile device to the sub-folder (language) needed. Search for the start file, in most cases index.html, start-here.html or similar. Then you can read and use links etc. on your mobile device as reading on a laptop. Please note that Xowa content does not work using a web browser.

Technical Aspects
Most modern smartphones can be used to host a WiFi network. However, not all WiFi chips of laptops or USB-sticks (and their drivers) support this feature. According to the Ubuntu Users Wiki [1], these WiFi chips do the job:
• chips driven by the hostap driver or
• chips working with a current mac80211/nl80211 sub-system
A detailed description on how to set up the laptop as a WiFi hotspot is given in the Ubuntu Users Wiki [1]. The procedure works with (L)Ubuntu 14.04 - 18.04 LTS.
• provide files access (e.g. via Samba, offering Windows-compatible file services) and / or
• run a webserver to provide browser based access on educational content (e.g. via Apache)
• share its Internet connection (e.g. if the Laptop has WWAN)
to mobile devices connected to the WiFi.


Thank you, Daniel Neumann, Labdoo Hubs Hamburg / Rostock, for contributing this text (

Windows look-alike user interface

For the explained reasons and advantages, Labdoo uses the Linux operating system. However, some users prefer a graphical user interface (GUI) which looks like Windows so that the learning curve for some users is even lower. In this page you will find a guide on how to install and configure the Lubuntu GUI to look similar to Windows.

Those using Labdoo Images for Cloning can stop reading here, as the images are coming with pre-installed Windows 10 themes and icons that can be activated.


Windows 10-look alike user interface might be for instance downloaded from here or from (download light and dark theme, icon set)

Unpack the archive and move the files using superuser rights to these two folders (you can open a terminal with ALT+CTRL+T and then type sudo pcmanfm [enter] to open a file browser from where you can move the files):

  • Move themes to /usr/share/themes
  • Move icons to /usr/share/icons

Check the rights to access and update them, if needed (right click on the file, and select Properties → Permissions → View = anyone; change = only owner; Access = anyone).


In order to activate the new themes, click on the Lubuntu-start button on the left bottom corner of the screen and select Preferences → Customize Look and Feel → select in the tab widget the Windows theme → click on the icon theme and select Winx-x.x.x → close the window.

To undo / switch back to the default Linux theme just select another theme (Lubuntu-default) and icon theme (Lubuntu) or other layouts that you may like.

NTP - set clock automatically via internet

The tool to be installed is named NTP – Network Time Protocol (open a terminal: sudo apt-get install ntp → Enter or alternativ via the software center) for Network Time Protocol.

You don't have to adjust anything else. The time is taken from web server. You are able to define time zone and server. Online access is needed.

NTP is already part of the Labdoo images and install scripts.

NVIDIA grafical drivers, problems and solutions

  1. If a computer is not able to boot and if you are not able to log-in sometimes you are still able to have access via terminal:
  2. Either using CTL+ALT+t (if logged in), CTL+Alt+F3 or follow the GRUB information using the recovery mode:
    sudo apt-get purge nvidia-current (Enter)
    sudo apt-get install linux-headers-generic (Enter)

  3. Preferences --> Additional Drivers --> wait a while and if proprietary drivers are offered for downlaod.
  4. NVIDIA driversfrom PPA (source) of developer community
  5. Herefor you have to add an additional source for software (PPA). Please be aware of potential risks of adding sources (PPA) to your computer:

    CTL + ALT + F3 (in recovery mode) or CTL + Alt + t if logged-in opens terminal

    log-in as user labdoo and password labdoo,
    sudo su (enter) + Passwort labdoo eingeben (enter)

    To add PPA for Ubuntu 14.04 / 13.10 / 13.04 / 12.10
    sudo apt-add-repository ppa:xorg-edgers/ppa (enter)

    To add PPA for Ubuntu 12.04 / 11.10 / 11.04 / 10.04
    sudo apt-add-repository ppa:ubuntu-x-swat/x-updates (enter)

    sudo apt-get update (enter)
    sudo apt-get install nvidia-current nvidia-settings (enter)
    sudo reboot (enter), um Laptop neu zu starten.

  6. If your computer is older (built before 2004) it does not make sense as this card is not supported anymore. It is worth a try to use either Lubuntu 12.04 LTS or to use the Labdoo Image for cloning for Lubuntu 12.04 LTS.

Open a terminal

Often you will read "open a terminal". Here is explained how to do so:

Either press at the same time the 3 keys CTL + Alt + t.

Or alternatively → System tools → click on UXterm or XTerm

The terminal window will be shown.

At the beginning of each line you can read name of the user @ name of the laptop, e.g. labdoo@labdoo-000004xxx. You are now able to type in your comands.

When executing a command line wait until you see again this beginning of a line.

To close a terminal either type “exit” → Enter eingeben, when the command is proceeded.

During the installation process of Lubuntu or during the boot process you are able to press CTL + Alt + F3 and you get access to the terminal level. Using CTL + Alt + F7 you get back.

Remove former Linux kernel releases

If you update to newer linux kernels the old kernels stay on the disc. Each kernel need about 60 - 140 MB. To remove them you have to open a terminal:

To rmeove former Linux kernels execute in a terminal:

sudo dpkg -l | grep linux-image (Enter)

The result should look like

ii linux-image-3.2.0-31-generic 3.2.0-31.50 Linux kernel image for version 3.2.0 on 64 bit x86 SMP
ii linux-image-3.2.0-32-generic 3.2.0-32.51 Linux kernel image for version 3.2.0 on 64 bit x86 SMP
ii linux-image-3.2.0-33-generic 3.2.0-33.52 Linux kernel image for version 3.2.0 on 64 bit x86 SMP
ii linux-image-generic

In this example you might delete the kernels 3.2.0-31 and 3.2.0-32 (the numbers might differ from your list, please exchange). The last 2 kernels with the higher release numbers shoud remain:

sudo apt-get remove --purge linux-image-3.2.0-31-generic (Enter)

Search files in all folders and delete them (optional)

Open a terminal (CTL + Alt + t) and execute

only to search and list: find ./ -type f name „Dateiname“ (Enter)

search and delete: find ./ -type f name „Dateiname“ -delete (Enter) (Be careful!!!)

Installation of VirtualBox

When you are installing VirtualBox the first time manually please follow these steps (if you are cloning you can ignore this wiki page):

After having installed VirtualBox you have to add the matching Extension Pack. Important: Please make sure that the release number of VirtualBox and Extension Pack are identical! For this purpose, start VirtualBox (either using the icon on the bottom left Lubuntu --> Run --> virtualbox (Enter) or by Accessories --> VirtualBox) and open Help --> About VirtualBox to see the release-no. of VirtualBox. Next step is to open File --> Preferences --> Extensions to see the release-no. of the Oracle VM VitualBox Extension Pack. Both must match, if not please follow the steps explained below.

Update, Update to a higher VitualBox release number

If the VirtualBox is only patched without upgrading to a higher version no further actions have to be taken. In longer intervals the (L)Ubuntu distribution upgrades VirtualBox to a higher version number. In such a case, the Extension Pack will not automatically be updated. For this purpose, proceed as follows:

    To Update the Extension Pack
  • First check the release number of the installed Virtualbox version →Help → About VirtualBox → you can read the version no. in the window in the format x.x.xx (e.g.. 5.1.34). For LTS releases of (L)Ubuntu often older versions are used due to reliability.
  • Next open in VirtualBox menu File→Preferences→Extensions and remove the former Extension Pack (mark it and click on the blue square with the red X)
  • Then download the matching Extension Pack from the homepage If you are not able to find the installed your version no. on this page, scroll down to VirtualBox Older builts. Click here and search in the next pages the matching release no. Extension Pack All Platforms → "Open with VirtualBox", and follow the steps to install it, ready.

WiFi cards will not be detected

1. Initial Considerations.

Before you check for the cause of a non-functioning wireless card (WiFi) please check that:

  • The wireless LAN (WiFi) function is properly activated via the hardware switch/slider (often on one side of the laptop) or via a function key on the computer keyboard,
  • There is a wireless card (WiFi) installed (often we get laptop donations without a wireless card), see below Check which WiFi chip is installed and check the manufacturer name. In case there is no WiFi card installed you can add one or use a connection via LAN (cable).

Sometimes older or very new WiFi Cards are not recognized automatically. The following check list provides a set of steps that you can try to fix this situation.

2. Check list.

  • Check if specific drivers are needed
  • Preferences → Software & Updates → Additional Drivers → wait a while
    → either "no additional drivers available" is hown → no further action should be needed, or
    → a list of availble drivers is shown → click the driver you want to use → Apply Changes

  • Check which WiFi chip is installed and check the manufacturer name
  • Open a terminal and execute:
    lspci | grep -i net (enter)
    to show chip set and manufacturer:
    lspci -nnk | grep -i net -A2 (enter)
    or in case of using an USB Wifi stick:
    lsusb (enter)
    Note: Some build-in WiFi cards are recognized as an external USB, so if in doubt try also these commands.

    To check if your WiFi card is supported:

  • Check if the Broadcom WiFi chip is not detected
  • If your WiFi card is based on the Broadcom chip set you are able to install:
    sudo apt-get update (enter)
    sudo apt-get install firmware-b43-installer (enter)

    After rebooting the system it should work. If not activate the driver by hand:
    sudo modprobe -r b43 bcma (enter)

  • Try installing Linux Backport Modules
  • Linux Backport Modules can be installed to get support for many older Wifi cards. The Backport Modules are already part of Labdoo Image for Cloning and

    A detailed list of the supported WiFi cards can be found here:

    To install execute in a terminal:
    for Lubuntu 12.04: sudo apt-get install linux-backports-modules-cw-3.6-$(uname -r) (Enter)
    for Lubuntu 10.04: sudo apt-get install linux-backports-modules-wireless-$(uname -r) (Enter)
    and for all Lubuntu versions: sudo apt-get install linux-firmware-nonfree (Enter)

    If it does not work you can try:

  • Try installing NdisWrapper
  • Details at:

    Please check, if

    • the 32 Bit or 64 Bit driver of the WiFi card matches with your Lubuntu version (32 or 64 Bit)
    • the .inf file of the driver is enclosed, e.g. Intel encloses .inf only in the .zip version, not enclosed in the .exe!

    Follow the instruction in the upper Wiki (please add here an English Wiki link).

    If this does not work try:

  • Try installing the native WiFi driver of the manufacturer.
  • Please search in web for more information.

acer - special keys are not detected

Some acer laptops (and Medion in Germany) have special keys e.g. to activate WiFi, but these keys are not detected.

From Linux kernel 3.2 or Lubuntu 12.04 there is a core module wistron_btns, offering the same functionality as before acerhk (not needed anymore).

wistron_btns has the advantage that it is part of the kernel. So installing and compiling is not needed. And 64 Bit systems are supported as well.

To use and activate open a terminal and execute:
sudo modprobe -v wistron_btns (enter)

Taken from:

apt-offline - update computer offline

There is the tool apt-offline. You can download an update at a place, where you have access to internet, e.g. at home. apt-offline allows you to easily upgrade or install new packages on your offline PC, by using another online PC.

To Install apt-offline (execute in a terminal, press ENTER):
sudo apt-get install apt-offline (Enter)

On the offline PC: sudo apt-offline set /tmp/apt-offline.sig
On the online PC: sudo apt-offline get C:\apt-offline.sig --bug-reports --threads 5
On the offline PC: sudo apt-offline install /media/USB/

On the offline PC: sudo apt-offline set abuse-offline.sig --install-packages abuse --src-build-dep --install-src-packages abuse
On the online PC: sudo apt-offline get abuse-offline.sig --no-checksum --bundle
On the offline PC: sudo apt-offline install /media/USB/

More info

User concept, add user student


When installing Lubuntu-Installation the first user created is labdoo (who is also administrator and should be reserved for the teachers, as this user may destroy the system by mistake). If you install via cloning or if you use the installation scripts the additional user student will be created automatically.

The user student kas less rights, e.g. is not able to install or delete software and is not able to destroy the system.

Here is the manuel way, how to create a user student:

Start here → System Tools → User + Groups → unlock → +add user → system password (labdoo) → student as name, e.g. withpassword labdoo → Account Type = Standard (as suggested) → Create → click on password (account disabled) → input of password labdoo and acknowledge → Change → optional: cahnge language of user student.

Open a terminal and type (by executing this zhe user student will become member of the group labdoo):
sudo usermod -aG labdoo student (Enter)

Please note:
Each new user takes disc space. So please do not create more users.

As a standard user you are not able to destroy a system by mistake (or at least it is very hard). The user labdoo (administrator) should only be used by teachers.

Each user has his own folder and files in the directory /home/....(name of the user). But the folder home/labdoo/Public is a public folder. All users should have access here. To go there open the file explorer → filesystem → home → labdoo → folder /Public (you can add a bookmark to navigate here more easily).

If you add content of your own in /Public there is a script to ensure all rights are set correctly.

In addition there is the user guest. guest needs no password to log-in. But guest is not able to change or store anything. When logging out all his input will be deleted automatically.

broken packages, interrupted installation, Update to new Lubuntu release

The following hints were taken from

The installation was interupted unpredictable:
sudo dpkg --configure -a (Enter, Password Enter)

“Broken” packages are reported, repare:
sudo apt-get install -f (Enter, Password Enter)

Update without upgrading to a new ubuntu release
sudo apt-get install dist-upgrade (Enter, Password Enter)

Repare “broken” packages or to delete the cache of the program list:
sudo apt-get clean (Enter, Password Enter)

To reload the program list again
sudo aptitude -f install (Enter, Password Enter)

Package administration is not usable anymore
Should the package administration become unusable during an upgrade or dist-upgrade you can use:
sudo aptitude -f install (Enter, Password Enter)

After an update of the existing installation:
sudo aptitude safe-upgrade -f (Enter, Password Enter)

After running a version upgrade to a new ubuntu version:
sudo aptitude full-upgrade -f (Enter, Password Enter)

After these statements you should always run
sudo dpkg --configure -a (Enter, Password Enter)

graphic card - check which graphical interface is installed

Open References → Monitor stettings for a first information. Open a terminal:

Show name / chip set:
lspci -nnk | grep -i VGA -A2 (Enter)

driver version
Show driver name and release version:
glxinfo | grep 'OpenGL version string' (Enter)

graphic mode (resolution)
Show the resolution set and all possible screen resolutions and the interfaces:
xrandr (Enter)

install Skype

To install Skype the source "Canonical Partners" must be activated. Otherwise you will get the message "Skype cannot be found".

Hint: If you installed the computer using Cloning of Images it is NOT necessary to activate the Canonical partners programs, as that was already done within the image. Please proceed to the next chapter.

Activate source Canonical Partners

Click on the Lubuntu-Icon (Start) in the lower left corner → System Tools → Lubuntu Software Center → click on the tool symbol in the right upper corner of this window (sometime click on the triangle first to show the tool symbol) → in the window opening click on "Open Software Properties" → click on Tab "Other Software" → make a hook to select "Canonical Partners", you will be asked for the administrator password → click on Close → there is a suggestion to re-laod the software list, please do so.

If you have added Canonical Partners you can start to install Skype:

Installing Skype

Open a terminal and type

sudo apt-get install skype (Enter, tayp password, Enter, answer next question using y)

Only to make sure, if you get the message "Skype not found": Did you add the Canonical Partner Programs as recommended above? Another reason might be you missed to update the software list. so open a terminal and execute sudo apt-get update (Enter).

To get a Skype start icon on the desktop:

Click on the Lubuntu-Start Logo in the left lower corner → click on "Internet" → the list of internet programs will be shown → right mouse click on Skype → Left mouse click on "Add to desktop" → a double click on the Skype icon on the desktop will start Skype.

More details →

monitor settings (advanced)

If the standard monitor settings of Lubuntu do not fulfil your needs try the tool ARandR, e.g. when you connect a 2nd monitor or a beamer.
ARandR offers you a nice user interfaces and advanced options e.g. to make both screens work as one large monitor or as two separted.

Since September 2015 ARandR is part of Labdoo Images for Cloning and of

You can install ARandA as follows:

  • open a terminal,
  • sudo apt-get install ARandR (Enter, password, enter)
  • or

  • via the Lubuntu Software Centre

virus scanner ClamAV

You should not need a virus scanner using Lubuntu. Linux usually needs no virus scanner due to the Linux security concept. There are very few viruses for Linux desktop in the web. Nevertheless some companies offer virus scanner for Linux, e.g. for file server being used also by Windows clients.

Also some edoovillages asked to have a tool to scan USB disc drives of pupils to remove viruses from USB drives of the students. So please install ClamAV for your projects (ClamAV will be installed if you use the installationskript or images for cloning).

So we recommend the license free, open source virus scanner ClamAV

Open a terminal and execute:
sudo apt-get install clamav clamav-freshclam clamav-docs clamav-daemon clamtk (Enter)

And you should install the Firefox Plugin Fireclam, so downloads will be automaticaly checked on viruses using ClamAV.