I've got a boot problem that I'd like some help with. I have a homebuilt computer with Gigabyte GA-870A-USB3 MB and Phenom CPU. I was using a M4 64GB SSD to run Windows 7 and several other mechanical hard disks for storage. Recently I began getting occasional blue screens so I replaced the PS. The blue screens stopped, but about three weeks later the machine wouldn't boot. I entered bios and found the SSD wasn't shown. I swapped to another SATA port and power suppy but the SSD appears dead. I removed the SSD, swapped the boot sequence to the CDROM, and inserted my Windows 7 disk. Now when I turn on the computer it stops at "loading OS..." and won't proceed farther. I then replaced the DVD drive but the problem persists. BIOS shows my mechanical drive and the DVDRW drive. I have a replacement SSD but the computer won't boot from the original windows install disk (OEM, not upgrade). Do I have a BIOS problem? What do I need to do to get W7 reinstalled? I appreciate any help you can provide.