So the intro video was fine, but getting to the main menu you only see that quarter of the screen?
BTW if you browse to the '..\Beyond Divinity\Static' folder in Windows Explorer, you can rename the 'intro.mpg' video file, to prevent it from playing each time the game is started.
Did you try disabling SLI / Crossfire (if applicable)?
Did you try setting the game resolution and your desktop resolution to be the same?
In Vista some people have had performance problems with more than 3072MB RAM. You could try temporarily reducing the amount of memory Windows sees (described in the topic below) and see if that makes a difference.
30-40 FPS in XP x86; 10 - 20 FPS in Vista x64There are some general troubleshooting tips in the topics below, which you may have seen already.
yet another "Game simply won't start!"-thread and
BattleFields N00b ?