How to Enable Task manager?

Hello,
Hai Friends i am using Windows Home Premium OS.Two days B4 i try to install one flash software through INTERNET at that time one virus is affect my system. suddenly i was delete that software that time i try to open task manager(CNT + ALT +DEL) but it was not show that task manager my system task manager automatically disable i dont know how to enable that task manager again pls give me any suggestion for my problem.. (I am using K7 Anti Visus) Lisence version also...