Getting Win-7 64 bit to run on this machine was a royal pain. One good post from thestereolab.com/ where they posted that to get Windows 7 running on the Gateway GT5628. Problem was this is only a problem with SOME machines ... not mine. I had already upgraded my machine to all SATA DVD's, a new video card, and a new 1.5 TB C disk (a Western Digital WD15EURS). I saw where some said you had to re-format the disk, so I tried that and no luck. I finally decided to switch to a spare 80 GB 10K disk drive (a WD740) and it worked perfectly. Then, I used Acronis to 'clone' the disk to the 1.5 TB one, and now I'm about 99%. Can't get my HP 4300 scanner working but that fight continues.