My girlfriend's computer (Compaq 2 years old) has a nasty problem. The CPU usage is 100 percent even there is no application running. I assume that it is a virus or a worm, so I used AVG antivirus+spyware (free versionn) and deleted 37 spywares and 3 virus threats. Even after AVG, the CPU usage didn't change so I used AVAST antivirus and lavasoft spyware system, but still no changes in cpu usage and computer is very slow. is there any other thing I could do to fix this computer?