Logon issue

Hi all,
I have a client that has a Win 2K system on a novell network. He needed to get some data off aof a similar system with a corrupted OS. He slaved that drive on the good system and got his data and then removed the drive. He rebooted the system and when he went to logon the system logged him out right after it completed the log on. He puts the slave drive back in and it works fine. But if he takes the drive out it wont let him in again. He has tried both local accounts and network accounts.