Change display manager login screen

In Ubuntu 11.10 (Oneiric Ocelot)

After installing another displaymanager, sometimes the loginscreen will be changed to. If you don't like the choice you made when installing e.g. KDE this is the command to run in a terminal:

sudo dpkg-reconfigure lightdm

Will prompt you to make it default. More information here:

• https://wiki.ubuntu.com/LightDM