I recently built a new computer for my son (specs below) and each time I tried to install windows 7 I would get past where it lets you select the drive partitions and it would go to copying windows files. Then during expanding files each time at a different spot my computer would quit. The monitor would go black and the drives would stop chugging away but all of the fans would stay active. I would have to hold down the power button to restart. I've already solved the problem having tried swapping ram and disconnecting all of the peripherials. I read the forums here and that is how I came to the conclusion that it was a heat problem. The setup would not stop each time at the same place but at different places during the installation (and yes I tried XP as well thinking it might have been a driver issue). Comes to find out that the old nvidia 9800gt video card that I had taken from another computer was overheating. I replaced it with a new nvidia 9800gtx+ and the computer now runs smooth.
Western Digital Caviar Black 500GB 7200 RPM 32MB Cache SATA 3.0Gb