2-yr old XPS 410 randaom crash?

Hi,

I have a my XPS 410 for about 2 years. There was a 32-bit XP installed on C drive and another 64-bit XP on G drive, and the dual boot had been running smoothly.

About 3 weeks ago, I see no usage of the 32-bit, so I reformatted the C drive and installed 64-bit XP from scratch and the whole system became really unstable since then. It will flash a blue screen (so fast that I couldn't read or take a picture) and reboot itself. This happens randomly, sometimes after working for maybe 30 minutes, 2 hours, 5 hours, sometimes after 8 hours working. But usually the crash happens within an hour of use. I just can't predict when it's going to crash or find a pattern of causing the crash.

I tried lower the power consumption (take off all external HD and accessories), swapping RAM (I add 2 gig RAM after the first year), duster the machine and motherboard, redo the OS installation with brand new HD, update BIOS, etc., but none of them can stop the random crash. The only thing I can think of that I haven't tried is putting on a new motherboard. Could anyone tell me what else I can do to fix this? It's been 3 weeks, and I really can't keep working with this random crash machine.

Truly appreciated,

Jason