I purchased a computer 2 weeks ago and put it together myself. It consists of;
i5 750 CPU
ATI 5770 GPU
2 x 2G G.Skill Ripjaws Ram
CM RC-690 case with included generic CM PSU
I recycled the WD 500G HDD from my old computer, along with the optical drive.
However since putting it together, I have had a consistent problem. When Windows 7 Ultimate 64x boots up in the mornings, or after any extended period of time, my system crashes directly after "Starting windows" (Just as it reaches the desktop).
The computer then resets itself like normal, but the process will just loop on and on.
if I manually turn of the computer however, then get the "start windows normally" prompt and select it, it will boot up completely fine and be fine until the next time it is off for a long period of time.
Thinking it may be the power supply; seeing it like takes time to "warm up" before it decides to work normally, I took it back to where I purchased the parts, and they did a full diagnostic for me.
None of the hardware was faulty, they crosschecked it with other parts and ran hardware tests for 2 days.
They didn't even charge me full price for the diagnostic because everything was fine. They said it would be a Windows 7 installation problem and to reinstall it. So i did; but i still have the same problem.
I am thinking perhaps it could be a driver issue. I have tried running msconfig and turning off all start up non windows processes and it still does it.
It could also be that you need to force the bios settings for the RAM. The motherboard likely defaults to 1.5V and if the RAM is specced for 1.65 you can have this kind of problem until you manually boost the voltage.
The other persons problem may have really been solved by the XMS3 RAM having a profile that the motherboard recognized and defaulted the voltage properly for.