Slow System

I was working on a pc that was having problems after installing SP2, we uninstalled SP2 but the system was really slow afterwards. We noticed in the Task Manager under Processes that an executable file named diskvb.exe was taking most of the resources. Have any one had this problem, if so how do you delete it, because when you try to delete it it just keep coming back. And most spyware removal programs do not recognize it.