Windows XP Pro SP2 - AMD 64 X2 4400+ - Asus A8R32-MVP Deluxe - 2GB OCZ XTC PC4000 CL3-4-3-8 - ATI Radeon x1900xt 512MB - Enermax Liberty 620W PSU I've just finished (on the weekend) a clean install of Windows XP Pro SP2 with all the updates and latest drivers for all my hardware. I built the PC back in March, this started happening a few months after that, and still continues now along with a host of other problems which I will explain. When I boot up my computer, the video card fan spins up real loud, then I hear the BIOS beep, it then spins down and POSTS, quiet as a mouse. This is a normal boot. 1 out of 4 boots I will encounter where the fan spins up, I don't hear a beep, and the fan continues to keep spinning in a loop until I force the PC off and boot if back up. The other time is when I just restart the PC in Windows. again, maybe 1 out of 4 tries ends up where the screen goes black, the light to the monitor turns amber and I don't hear the single beep at the BIOS, so it just sits there at the black screen until I shutdown manually. Besides this, the PC has always run normal in Windows/Games. It was only when booting up or restarting. Now, I've recently had the PC completely freeze/lockup multiple times while running 3DMark 2006, which it never has froze before the many times I ran it earlier this year. It froze at the detecting hardware phase and again in between tests. Then again today while playing Medieval 2, the game froze during a battle, sound stopped, video stayed frozen on the screen. There was no mouse/keyboard interaction at all, to which I had to manually shutdown. This is not a heat problem, as PC so damn cool, I can't believe it myself. When I open the case and touch the inside of the case it's cold to the touch. Also the airflow is cold. My temps are low. I'm suspecting a couple things, one thing more than others, but I want to get the opinions of others. What course of action should I take? I don't have spare parts, so it's difficult to swap around anything. I am also within my 1year warranty for a lot of parts so I want to solve this now rather than later. Thanks.