Task manager button is gray

When I press atl-crtl-delete the windows screen pops up like normal with the option for shut down, lock, etc. only that the task manager button is shaded light gray like it's unavailable and doesn't do anything if you try to click it. It doesn't click.... any ideas? I did have a nasty XP Police virus that I removed with Counterspy. The problem started just before I removed the virus. I presumed it was written that way to protect itself from being shut down.