Tell us your PCs specs pls so we can help you, I have a laptop with a 512MB graphics card, and an i5 2.5Ghz turbo boost 2.9Ghz and can run the game on medium settings, oh and if you turn off desktop composition in windows it disables all aero features while the game is running and takes quite alot of load off the graphics card that can be used for the game reducing lag and allowing you to turn settings up quite alot