Help for free cookie

for some reason when i got back from texas i went on my computer played some CF,mw2,and CA and my CA game froze so i pressed ctrl-alt-delete to bring up task manager but were is task manager it was there a week ago but now its gone
so i click on search files and type task manager it comes up i press it and it says
Task manager has being disabled by your anministrator
WTF im the only admin on my computer and i locked my computer before i left so wtf how do i un-disable it

It's a virus. Just reformat your computer.