Demo Issue Black screen

[JordanTate]

Since installing I have encountered a major problem. The demo starts fine, I get to the main menu, Create profile and start a new game. Upon doing so the game loads "Daniel" and his speech. The subtitles lag, reading the previous line when its already onto the next. Eventually a candle fades in and a dim view of a room, Daniel finishes his speech, the game fades back out into a totally blank screen and bam... nothing.
From there i must close the game through task manager, which says the game is not responding.

Ive tried numerous things, changing graphical settings all to low including resolution. Turned v sync off. Turned SSAO to 4 samples and even off. Re downloaded and reinstalled, defragged, deleted .CFG file rebooted pc and left settings on default. I havent tried installing drivers, I did check for new drivers but the most recent for my card was back in Febuary and they are already installed. Nothing is working and always the same problem.

My system specs are as follows, and to my belief they are more than the requirments:

Intel Q6600 CPU @ 2.4ghz (4 CPU's)
3 Gigs of RAM
ATI X1950XTX 512mb

Help me find a solution for this fustrating problem thanks!