Vista - Vista ultimate 64 constant reboot

Hello! I need some help!
I built my system running Vista Ultimate 64 with
Abit IX38 Quad GT mb,
QX6700, 8GB of DDR2 1066 memory,
4 500GB SATA hd,
2 9600GT 1GB vc.
At first the system ran ok,
then I got a... video driver stopped responding error
then memory dump crashes started to happen.
I thought it was because of the video cards being SLI and the mb is crossfire type that triggered the problems.
I bought a new Asus P5N-T Deluxe mb and replaced the Abit mb.
After booting up with the new Asus mb, it worked for a short time
now it won't boot up at all after I got the latest windows updates last week!
It is now in constant reboot mode!
Can't go into normal boot, safe mode with networking or safe mode at all.
I tried to use the DVD to repair it,
ended with a message of...window is fixed and should be able to boot message.
But when it boot up, it will go only as far as the Vista window with the horizontal scrolling bar then to an abrupt stop
then blue screen which is so fast and I can't read the error messages.
I tried for over a week using various methods to get in to backup my information and failed.
Last weekend, out of desparation, I installed Vista on one of the backup drive and everything was fine until I got the latest update and now it TOO is doing the constant reboot thing!
I do not want to reinstall Vista onto the original drive which will wipe out all the information I have on it now.
Anyone has any idea as how to get the drive to boot so I can back up my information prior to reformat and reinstall Vista?
Just for kick, I tested the Abit mb on my wife computer with the exact same set up except only one 1GB video card and it's working fine with only 1 crash after installation of the latest deadly windows update.
I had to use her DVD to repair it then it is still working after a week!
I guess it was Windows fault all along! Thank you!

Remove all your memory except for 1 stick. Reinstalling to the second drive , set your options for auto update during install to NO. When you are up and running - Have you checked to see what the updates you are installing are. Video Card Drivers and Audio Drivers are generally less of a problem if you download them directly from the Manufacturers websit. Check your update settings. They should on check for updates but let me choose what to install. Hide driver updates.

Norm