Hi everyone. I'm new to this but I will try to explain my problem as well as I can. I have recently received my PC back from repairs and I noticed that whenever I play Cod2 or Cod4 ONLINE, after a while the PC freezes. I can't Alt+F4 or go into task manager. It just freezes completely and the sound keeps looping. Each time I have to manually restart my PC from the button. Single player works fine for both games and VGA temperatures aren't a problem since I've tried keeping it as cool as possible and the problem still occurred. The VGA is also not the problem cos I've tried 3 different ones, a 280GTX, 285GTX and now I got a 512MB 9600GT, and the problem still occurs. I've also noticed some visual bugs in some games, visual bugs that appeared with all the 3 different VGA's installed. I noticed that in BioShock2 some water ripples appear with pixels and bright lights emitted from broken electricity cables appear in like a shutter mode. In Splinter Cell Conviction, some surface reflections also appear with pixels. In Assassin's Creed 2 whenever a bright white light appears in a cinematic, the image is like getting constantly refreshed from top to bottom. As I already said the VGA's are fine since they are all new. Even the Mobo is new although I really don't know how to be certain the issue is not related. Here is my rig: Manufacturer: Custom Built. Processor: Intel Core2Quad Q9550 @ 2.83GHz. Memory: OCZ Blade 4GB DDR2 800MHz. Hard Drive: Seagate 500GB + a Maxtor 120GB which is always empty. Video Card: 9600GT 512MB Operating System: Windows 7 Ultimate 64-bit. Motherboard: Asus P5QD Turbo. PSU: 750W NOX Extreme Pulsar Thanks for your time and attention.