1. Try this;

http://www.windowsnetworking.com/kba...XPHomePro.html

try the gpedit first, and only then look at the registry if you are happy to do some, but as ever, tweaking registry can seriously mess up your PC.

2. go to

c:\windows\system32 or c:\winnt\system32

look for taskmgr. Is it there?

If it is, can you run that command, or from right-clicking the task bar, and selecting task manager.

If the file does not exist, then get you XP CD, search the CD for taskmgr, and add it to your system32 directory.

Let me know if this is helpful or not.