"apt-get install kde kdm"
If kdm is already installed, then do "dpkg-reconfigure kdm".
Select "kdm" as your default display manager. (If it doesn't take, try
again, select one of the other managers, then repeat the process a final
time and select kdm.)
If kdm doesn't start, either reboot or "/etc/init.d/kdm start", then at
the login screen make sure KDE is your window manager before logging in.
This does not work... I hav gdm and xdm installed, I always see the lines
starting kdm....
starting gdm.... (gdm not default manager)
starting xdm.... (xdm not default manager)
and thats all, then I have to login on the console. When I make a
dpk-reconfigure kdm, and I change gdm, then really strange things happen. But
ok, thats nonsense.