Help with A7V8-X

I'm having trouble with a machine a co-worker brought for me to look at. It's a custom built box that I built for his son about two years ago. His son claimed it completely stopped working last week so he took it to Best Buy. The techs at BB told him he needed a new mobo so they sold him the ASUS A7V8X-X to replace his older A7V. After about a week the tech at BB called to say that they were unable to fix the box and they didn't know what the problem was.

My coworker brought the box in to me and I'm having some bizarre problems when trying to install Windows XP to the original hard drive. When it gets to the part where Windows says "checking hard drive" the computer freezes up. I've tried multiple OS's and disks, and even tried a ghost image of my hard drive but nothing works. I then had him go and buy a new Maxtor hard drive and the same thing happens. I am able to format and partition the drive using the MaxBlast software, as well as with the Windows XP disk, but I can't go any further than that.

Any ideas? Power perhaps?