It's hard to diagnose, as it could be a hardware problem or a driver problem. I'd start by downloading and installing updated drivers for all the hardware, esp. the video, network, and sound devices. If that doesn't help, I'd swap out one of the RAM boards at a time in case one is defective. (Alternately, you could download and use memtest86 to test the RAM. This would also help determine whether it's a hardware problem or a software problem, as a software problem wouldn't affect the memory test.)
I tried posting this in the General help forum, but no-one responded. So, I will repost this here....
I just built this new computer:
stock minitower and 450W PS
XFX 630i w/GeForce 7150 mb
Intel Pentium D940 3.2 Ghz CPU
Masscool 8W553 cpu fan
Hitachi 500Gb HD
GeForce 8500GT PCIe video card
20x DVD/RW drive
2MB Corsair PC6400 memory
I loaded XP pro SP3, and everything was fine for maybe 2 hours. I ran the set up disks for the mb and video drivers that came with the products. I was loading WOW, and setting up Ventrilo when I got the blue screen with the white text, and it crashed. I rebooted, and I got the boot in safe mode screen.
When I chose safe mode, I see all the drivers load, but it just hangs and won't start. When I chose Normal, it goes black and hangs or reboots. Previous configuration, same thing ... it hangs or reboots. Last night after this happened, there were a couple occasions when Windows would load and I'd get the GUI, but this would only last for maybe 10 mins before it would crash.
I did try to reload XP Pro. The disk would boot, and the drivers would load, but then it would say 'Starting Windows' and it would just hang there.
Is this a Power supply problem, or a BIOS problem or even a harddrive problem? Those are the leading culprits in my mind.