Restore Ubuntu 16.04 Login Screen

I installed Ubuntu Kylin Theme but I want to restore the original login in screen for ubuntu, I tried to uninstall the theme, purge and reinstall the lightdm and also change the default to gdm with dpkg-reconfigure but I always get the Ubuntu Kylin login screen.

EDIT:

I tried to see the configuration in Ubuntu Tweak but only show the default login screen configuration even showing Ubuntu Kylin when I boot the computer.

Solution 1:

kylin-greeter is a version of LightDM greeter, and to switch back to the default greeter ( which is unity-greeter ) one must tell lightdm which one to use via configuration file.

What you want to do is edit ( or create if it doesn't exist ) the file /etc/lightdm/lightdm.conf

Basic steps ( done from terminal )

1. Open the file with your text editor. You can use nano because it's easier. sudo nano /etc/lightdm/lightdm.conf

2. If you have [SeatDefaults] line, go to step 3. Otherwise, add this line.

3. Bellow [SeatDefaults] add greeter-session=unity-greeter line.

4. Save with Ctrl + O. Exit with Ctrl + X .

5. Reboot, or go into TTY1 ( via Ctrl+Alt+F1 ） ， login there and restart lightdm with sudo service lightdm restart