I've been playing with some of the settings on simple LightDM manager, and I'm not really sure I like what I've done. I've uninstalled LightDM manager but settings remains.

How can I restore LightDM settings to their defaults?


I've had a look at this issue and it looks like simple-lightdm-manager affects one file called unity-greeter.conf.

  1. Lets start by opening up a terminal, start typing "terminal" in your unity dash to see the option or press ctrl+alt+t

  2. Lets go to the correct directory:

    cd /etc/lightdm
  3. Now lets make a backup of the file before we make any changes:

    sudo cp unity-greeter.conf unity-greeter.conf.bak 
  4. Now we need to open up this file and see whats changed, type/copy this:

    sudo gedit /etc/lightdm/unity-greeter.conf

    The file should look like below, but I'm guessing your background and logo lines will look different:

    # background = Background file to use, either an image path or a color (e.g. #772953)
    # logo = Logo file to use
    # theme-name = GTK+ theme to use
    # font-name = Font to use
    # xft-antialias = Whether to antialias Xft fonts (true or false)
    # xft-dpi = Resolution for Xft in dots per inch (e.g. 96)
    # xft-hintstyle = What degree of hinting to use (hintnone, hintslight, hintmedium, or hintfull)
    # xft-rgba = Type of subpixel antialiasing (none, rgb, bgr, vrgb or vbgr)
    font-name=Ubuntu 11
  5. Now either replace everything in your file with the code above, or replace the background and logo lines with the ones above. Then save and log out.

Be careful not to add anything else to this file it could cause adverse effects to your log in screen or even prevent you from logging in

The code above is the default file that loads with a fresh install of Ubuntu 11.10.

  • Hi, I try to open unity-greeten.conf sudo gedit /etc/lightdm/unity-greeter.conf but it blank page in gedit. I have problem with login/out in Ubuntu 12.04. alway show this message: Your system is running in low-graphics mode. how to fix it?
    – Fanoy
    Jul 21 '12 at 23:07
  • The file above worked well in Ubuntu 11.10, I haven't tried it in 12.04. But the blank page you see is because the file doesn't exist in 12.04. Your "System is running in low-graphics mode" is probably best to ask another question! good luck.
    – captain_G
    Aug 26 '12 at 21:10

I had a problem with my box getting stuck at the Ubuntu logo. Hitting Alt+F1 took me to a prompt where I ran sudo apt-get --purge remove lightdm gdm -- I'm using gnome, not Unity. Be careful with this -- watch what else Ubuntu wants to remove.

In my case, Ubuntu removed gnome-core.

After it was done, I ran sudo apt-get install gnome which brought back gdm, gnome-core, etc with default configs. A reboot gave me back gdm and no longer was I stuck at the Ubuntu logo on boot.

Be careful with apt-get --purge remove!

  • 3
    I am not sure how this answers the question "How to restore LightDM settings?" Care to explain?
    – jokerdino
    Sep 4 '12 at 4:36
  • with --purge, Ubuntu is deleting settings -- then with a re-install, you'd get the original settings back. In my case, i didn't want lightdm but rather gdm -- but it's the same principle for all Aptitude packages. Sep 14 '12 at 2:27

sudo apt-get -o Dpkg::Options::="--force-confnew" install --reinstall lightdm will do it for you.

  • Didnt seem to work im afraid, i did a complete restart but i still have a modified login screen.
    – richzilla
    Oct 31 '11 at 21:45

LightDM loads settings from multiple places. This list from the Ubuntu documentation page shows the load order, with later ones in this list overriding earlier locations.

LightDM configuration is provided by the following files:

/usr/share/lightdm/lightdm.conf.d/*.conf # System/package configs
/etc/lightdm/lightdm.conf.d/*.conf       # Package/system administrator configs
/etc/lightdm/lightdm.conf                # Generated by installer once, overrides others

System provided configuration is stored in /usr/share/lightdm/lightdm.conf.d/*.conf and is not normally user editable. System administrators (with sudo) can override this configuration in /etc/lightdm/lightdm.conf.d/*.conf and /etc/lightdm/lightdm.conf. Files are read in the above order and combined together to make the LightDM configuration.

For example, if you want to override the system configured default session (provided in /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf) you should make a file /etc/lightdm/lightdm.conf.d/50-myconfig.conf with the following:


An example file showing all the possible configuration is provided in /usr/share/doc/lightdm/lightdm.conf.gz.

If you went through the installer and filled out auto-login/etc then it was probably written to either /etc/lightdm/lightdm.conf or /etc/lightdm/lightdm.conf.d/*.conf. You can safely remove the /etc/lightdm/lightdm.conf to revert to system settings, and if you haven't made any changes to stuff in the /etc/lightdm/lightdm.conf.d/ directory then only the 50-ubuntu.conf and some other package configs should be in there.


I found out that it's because during my installation of Ubuntu 11.10, I checked the, "Encrypted Home Folder," option. In doing a search about Simple LightDM Manager, I found out that if your Home Folder is encrypted, the app doesn't have privilages to the files that it needs to change your LightDM settings. I've changed the permissions of the files to hopefully allow Simple LighDM Manager to access them, but all I get is a black screen with the login prompts to the left. I can change the color, but cannot add an image of any type to the login screen. I tried removing Simple LightDM Manager and reinstalling the regular lightdm as described in the above answer, but to no avail. I am somewhat new to Ubuntu, so, I suppose I'm stuck with it, as there doesn't seem to be a way other than reinstalling the OS all over again, and NOT checking the encryption option whilst installing.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.