After a long session in Knoppix (installed on hard drive). I shut down then came back to the box to start. Everything was going fine until the beginning script stopped at a logon prompt before the GUI came up. I am new at Linnux but I am trying to learn as much as possible. I have not had any problems for a couple of weeks. I was doing an apt-get upgrade in this session, though I've done them before with no problems. Just before the logon prompt the text was;

Starting K Display Manager: KDM
Not starting X display manager (XDM); It is not the default display manager

Debian GNU/Linux Testing ?unstable Newbox tty1

"Newbox being the name of the computer"

Can anyone please help? Are there some commands or actions I can do at the shell prompt to restore the GUI?

Thank you in advance,
Chip