-----Original Message-----
You could be infected with one of these worms:
W32.Spybot.Worm
http://securityresponse.symantec.com/avcenter/venc/data/w 32.spybot.worm.html
(e-mail address removed)
(e-mail address removed)
http://www.dougknox.com/xp/utils/xp_emerutils.htm
Creates usable copies of REGEDIT, MSCONFIG and Task Manager
If you are sure you don't have a virus, then see this links:
Enable the Task Manager (Line 51)
http://www.kellys-korner-xp.com/xp_tweaks.htm
Enable/repair the Task Manager (#113)
http://www.kellys-korner-xp.com/xp_tweaks.htm
Allows you to enable or disable Task Manager for the Current User
http://www.dougknox.com/xp/utils/xp_taskmgrenab.htm
Lift Restrictions - Task Manager, Regedit and CMD (Line 275)
http://www.kellys-korner-xp.com/xp_tweaks.htm
Troubleshooting the Task Manager
http://www.kellys-korner-xp.com/xp_t.htm#tm
.