|Agreed. Boot to the Widows install DVD, choose Custom and then Format/Partition. Delete all partitions (Assuming you have backed up anything that can be saved from the drive). Create one new partition and format it to NTFS (Quick Format) and proceed with the install. If you plan on making more partitions, leave the rest of the drive raw until after Windows is installed, you can them use Disk Manager within Windows to create and format the remaining partition(s).|
If you fail at any point, you need to test some of your hardware. First boot to a CD with Memtest86 on it to test your RAM, let it run through all tests. No errors are acceptable. If that tests Ok then proceed to test your hard drive with your hard drive mfg's test utility (Seatools from Seagate will work on most drives if needed) via a bootable CD (DOS version) which you create.
Report back with results.
You have to be a little bit crazy to keep you from going insane.