jeremym

I dont know what the problem was for you in particular but i had this issue as well. Mine happened whenever a UAC prompt came up. The screen would go black and you obviously couldnt see anything.

I found that if i hit enter i would go back to my desktop. It was an nvidia display driver problem that seems to be fixed now with later drivers.

Just figured i would share my results of fixing a problem that might or might not relate to yours.