There was a power outage while my computer was on (booted into vista). Now, the computer will turn on and reach the OS selection screen, but neither of my two operating systems (win 7 rc, win vista ultimate) will boot. When selected, they both just go to a black screen infinitely. They reside on separate hard disks.

Any ideas as to what's happening or how to fix it?

Unfortunately, I do not have a set of spare RAM or a spare Graphics CArd. However, I have discovered that it boots fine into XP, just not Vista or 7. Windows Boot Repair doesnt seem to do much of anything.

Yeah, I have a triple boot with XP Pro, Vista Ultimate and 7 RC. XP boots but the other two do not.

I have 4 Hard Drives:
Disk 1: Windows Vista & Windows XP
Disk 2: Windows 7
Disks 3/4: Data Partition (Dynamic Partition on 2 Drives)

Other Hardware in case its important
4GB Ram
Nvidia 8800GT Graphics Card
2.66Ghz Core 2 Duo

I just gave up and restored Windows 7 to an image I made right after installation a few months ago. Still have no idea on how to get Vista Working. I tried using the Startup Repair utility on the Windows 7 Installation DVD on both operating systems and it couldn't find a solution for either.