Software & AppsOperating SystemLinux

How To Restore LightDM Settings to Default

Ubuntu 15

LightDM is a popular display manager used by various Linux distributions including Ubuntu. It is highly customizable and allows you to change the login screen background, logo, theme, and more. However, if you’ve made some changes that you’re not happy with, or if something has gone wrong, you might want to restore LightDM to its default settings. This article will guide you through the process step by step.

Quick Answer

To restore LightDM settings to default, create a backup of your current settings by copying the unity-greeter.conf file. Then, open the file in a text editor and replace its contents with the default configuration code provided in the post. Save the file and log out to see the changes. If you’re still encountering issues, you can try reinstalling LightDM or checking the configuration file load order.

Backup Your Current Settings

Before making any changes to your system files, it’s always a good idea to create a backup. This way, if anything goes wrong, you can easily revert back to your original settings.

Open a terminal by pressing Ctrl + Alt + T or by searching for terminal in the Unity Dash. Navigate to the LightDM directory by running the following command:

cd /etc/lightdm

Next, create a backup of your current LightDM configuration file:

sudo cp unity-greeter.conf unity-greeter.conf.bak

This command uses the cp (copy) command to create a copy of the unity-greeter.conf file. The sudo command is used to execute the command with root permissions.

Restore Default Settings

Now that you’ve created a backup, you can proceed to restore the default settings. To do this, open the LightDM configuration file in a text editor. You can use any text editor you prefer, but for this guide, we’ll use gedit:

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

Replace the contents of the file with the following default configuration code:

# 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

This code sets the default background, logo, theme, font, and other settings for LightDM.

Save the file and log out of your current session to see the changes.


If you’ve followed the steps above and are still encountering issues, there are a few other things you can try.

Reinstall LightDM

If you’ve installed a tool like Simple LightDM Manager and then uninstalled it, but the settings remain, you can try reinstalling the regular LightDM package. Run the following command:

sudo apt-get --reinstall install lightdm

This command uses the apt-get package manager to reinstall the lightdm package.

Check Configuration File Load Order

LightDM loads settings from various locations, including system/package configs and administrator configs. The load order is as follows:


If you’ve made changes to multiple LightDM configuration files, you can remove any custom configuration files in the /etc/lightdm/lightdm.conf.d/ directory to revert to the system settings.


Restoring LightDM to its default settings can be a bit tricky, but with the right guidance, it’s certainly doable. Always remember to make a backup before making any changes to your system files. If you’re still having trouble, don’t hesitate to seek help from the Ubuntu community.

Remember, the key to a successful system administration is understanding what you’re doing and why you’re doing it. Always take the time to learn about the commands and files you’re working with. Happy computing!

How do I open a terminal in Ubuntu?

To open a terminal in Ubuntu, press Ctrl + Alt + T or search for "terminal" in the Unity Dash.

How do I navigate to the LightDM directory in the terminal?

To navigate to the LightDM directory in the terminal, use the command cd /etc/lightdm.

How do I create a backup of the LightDM configuration file?

To create a backup of the LightDM configuration file, use the command sudo cp unity-greeter.conf unity-greeter.conf.bak.

How do I open the LightDM configuration file in a text editor?

To open the LightDM configuration file in a text editor, use the command sudo gedit /etc/lightdm/unity-greeter.conf.

How do I restore the default LightDM settings?

To restore the default LightDM settings, replace the contents of the unity-greeter.conf file with the default configuration code provided in the article.

How do I reinstall LightDM?

To reinstall LightDM, use the command sudo apt-get --reinstall install lightdm.

How can I check the LightDM configuration file load order?

LightDM loads settings from various locations. The load order is /usr/share/lightdm/lightdm.conf.d/*.conf, /etc/lightdm/lightdm.conf.d/*.conf, and /etc/lightdm/lightdm.conf.

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