A strange problem happening after update. After I updated Ubuntu 12.10, I restarted. After boot, i realized that there isn't any login screen at all. I mean no login screen, just an Ubuntu background. I tried restarting several times, but still no login screen
If you would like to use the GDM login screen (Gnome's default), install it using these commands:
In order to do this you will have to press CTRL-ALT-F1 and login with your username and password.
If you want to use LightDM, try this: