I have the same Problem I have a ASUS 4890 one of the new ones with the two red fans on it.
I loaded Windows 7 64bit from windows xp 32 bit, with ISO file from student version, everything to load great
but when i had to restart after windows wanted to after loading video drivers it went to a BLACK SCREEN with my cursor
thats it, so I restarted in safe mode with networking, I looked on all the forums to find my fix to the problem and tried just about everything but im open for new ideas, so I removed the video drivers in safe mode and restarted the computer and Windows 7 loaded, and it found the video drivers automatically so it wanted to restart again so I did and then it went to a black screen again. so now i am stuck