Issue with Botting Vista DVD

Hello there !
I own a Windows Vista Business System Builder Edition Pack and had it fully
setup with a dual boot installation with XP prof.
But then one RAM stick broke and with it my Vista won't boot either. I get a
bluescreen starting it up so i thought maybe a repair installation or the
normal tools like fixmbr and such would help me.
I booted up the Vista installation, it says "windows components are loaded"
on a black screen with "windows 2k" lookalike bar. Then i get to the coloured
screen and then the pc reboots.
I don't get to choose anything, it just restarts.
I don't get the point because i installed it with this disc without any
problems. The disc is clean also, so no scratches. This is the 2nd time i
pulled it out of the box.

I used the disc that comes within the plastic case, not the paper one
labeled "OEM preinstallation Kit" because i don't think that it'll be useful
now "after-installation".

Has anyone else heared of such an issue ?!

I'm willing to sacrifice my Vista installation, theres nothing important for
me on it, but the **** DVD won't boot to a single menu. My XP discs work
fine, but not the Vista one.

I hope anyone can help me with this kind of problem.