Need help cant install Windows 7

I have a Core 2 Quad 8300 with a Gigabyte GA-EP43-UD3L with 6GB of DDR2 memory. Everything was working fine and I did the latest windows updates not sure which one they were but when it restarted i got the error for no MBR found. So I go and get my Windows 7 install CD to try a startup repair and Boot to the CD. CD boots and displays the starting windows splash screen and then show the normal blue splash screen but it sits there for a minute or so. Then Starting Setup finally comes up but then the computer restarts.



This has me totally stumped so i decide to boot to a Ubunutu 10.10 USB like key I have and it boots to that just fine so I back up all my files i needed. then I replace the hard drive and try to install windows again with the same results. Cant really find any info on this so I begin unplugging all unnecessary devices inside the tower. Tried a new windows 7 cd as well as a windows installer USB key all with the same result. Lastly I replaced the video card as well as playing with different setups of memory and extra memory I had along with unplugging everything from the mother board. The only things plugged in are the CPU, Video Card, Ram, and PSU and I try to boot to the USB Key and same result again.



The only other thing i tried was wiping my HD and actually installing linux on the drive and it seems to work fine with everything but still cant install windows 7 for some reason. Also tried 4 different Bios Flashes still with no success.



I am really stumped on this and im down to it being the board or CPU which is only 1 year old if anyone has any ideas I would appreciate it I need the PC back for School in Janruary.