yesterday my computer (with windows vista enterprise) was up and running. Suddenly there was a power breakdown and as it should be the computer restarted. While it was restarting another power breakdown occured... now Vista woun't boot anymore...

This happens:

I have a dual boot system (xp and vista), when I choose Vista it continious and the loading screen of Vista appears, then when normally the login screen appears there is only a black screen.

The vista repair tool doesn't work... but I still can use the computer via Windows XP, so I can repair it probably by myself... I only don't know what to do? Wich files are damaged?