My computer freezes at random intervals when I'm using it the screen will freeze and the light on my G5 mouse and keyboard will turn off, and I'll have to restart the computer. This happens less when I'm surfing the net, and more when I'm playing a game, for example i only got to the loading screen on L4D and it froze. I've never had the computer not freeze at some point when I've played a game, which usually takes 15 minutes or less I've run memtest on each stick of ram individually, and they both passed. I recently replaced my 8800 GTX with a 9800 GT because the former broke(my fault), and I've reformatted my computer 5 times this week, with the problem persisting, any ideas on whats wrong? Also, when I leave the computer off for an extended period of time, like overnight, the first time I turn it on, the computer will not post, when i push the reset button, it will post and starts up normally
Case: 3D Aurora 570
Mobo: Gigabyte GA-P35C-DS3R
CPU: Intel Core 2 Quad Q6600, 2.4ghz
Ram: Corsair 2gb PC6400 5-5-5-12
Graphics: XFX 9800 GT
HD: Seagate barracuda 1.5TB
Pwr: Antec True Power Trio 650 Watts
Screen: 2 Samsung SyncMaster 204BW
Case: 3D Aurora 570
Mobo: Gigabyte GA-P35C-DS3R
CPU: Intel Core 2 Quad Q6600, 2.4ghz
Ram: Corsair 2gb PC6400 5-5-5-12
Graphics: XFX 9800 GT
HD: Seagate barracuda 1.5TB
Pwr: Antec True Power Trio 650 Watts
Screen: 2 Samsung SyncMaster 204BW