I tried to enable the Task Manager

Hi all
I tried to enable the Task Manager if it was put out of action, but I got that when I tried to do it, my Registry Edit was also disabled.
I recognize this is most likely due to a virus; however I scanned my PC many times with McAfee Antivirus 2010 but found nothing.
But, I'm having problem to enable the regedit.
Also,I attempted every way listed but I continue getting error messages. This is the major one:

Windows Script Host
Script: C:UsersEdinDestopreg_enable.vbs
Line: 22
Char: 2
Error: Invalid root in registry key
"HKEY_USERSS-1-5-21-3342531627-3480793956-2812775554-1000Soft
wareMicrosoftWindowsCurrentVersionPoliciesSystemDisableRegis
tryTools".
Code: 80070005
Source: WshShell.RegDelete
OK
What should I do now? Please help me to solve it.
Thanks a lot.
