taskmgr.exe - Unable To Locate Component

Ok the current OS I'm running right now is Windows XP Professional, Service Pack 1 (5.1 - 2600).

When I try to press ctrl + alt + delete I get this error message.

taskmgr.exe - Unable To Locate Component
This application has failed to start because WDMDBG.dll was not found. Re-installing the application may fix this problem.

This happened like last week and I don't know how to fix it? Could something have deleted this dll file? Damn freakin me out man thinkin that I might have dl'd some virus.

Do you run any Anti Virus software, or Firewalls? if so, are they still running?

also: download this program and run it. If you have way too many ports open you have a virus/trojan running.
Active Ports
http://www.protect-me.com/freeware.html

I have Norton 2003/ZoneAlrm running