A lot of Kubuntu users hate LightDM and want to use KDM the default Login screen on KDE. But how to do this? It is too easy just open your terminal (or Konsole on KDE) and add the following commands.
sudo apt-get install kdm
Maybe you’ll see a message to choose between [KDM] and [LightDM], if this message doesn’t appear, add the next command and choose witch one you need:
sudo dpkg-reconfigure kdm
Now, everything became OK … But if you faced any problem you can leave a command describes your problem. That’s everything, see you 😉