Did you have the 17" screen turned on? I had the same issue using a 46" LCD TV and forgetting I had an old 17" monitor plugged in as a secondary display. I reinstalled 3 times before I thought to turn on the 17" monitor which it turned out was set to be the primary display.
I think it was "disconnected display 2" that helped. I had the same issue, installed 3 times, every time it would end up with the black screen with the beta message in the bottom-right corner. Finally I thought to turn on the (unused) second display, and there it was. Windows 7 has...