game crashes

[vambi]

Hi there

After few minutes the game freezes but I can still hear some backround sounds, and when I press any button it crashes back to desktop and there is no error message or anything. I have updated the graphics card driver and tried running the game in lowest quality (the launch menu recommended medium). The game is a bit laggy too, so maybe my computer is just outdated for this game, I don't know.

specs:
Windows 7 32-bit
AMD athol II X3 425, 2.69GHz
4.0GB @ 255MHz
256MB GeForce 7300 GS