Symptom: When you open a DOS shell or if you run some programs in the DOS shell, you will get an error: Cannot load VDM IPX/SPX support
Causes: On Windows 2000 (maybe Windows XP and others), when you install CSNW and Novell's Netware client, it adds extra stuff to your autoexec.nt file. When you uninstall the client, it leaves a few turds around on your system (don't they all?) that could cause problems.
Solution: Edit your %SystemRoot%\system32\autoexec.nt file and delete three lines.