games always minimising

Hi, i built a pc in february this year and all was working well untill i tried to play GTA 3. Every time i tried to load the game it would minimize and only on the odd occasion after persistant ALT, TAB would it maximise. This is now happens with all games except counterstrike. I have a GeForce2 MX400 64mB graphix card and sufficient proccessing power(AMD Athlon XP 2000+). I have tried many versions of drivers to no avail, please help.

You may have some sort of spyware installed on your computer…