Low FPS issue.

[plutomaniac]

OK, maybe this is a graphics driver problem. Do these:

1) Download Driver Sweeper and install it. Do not run it yet.
2) Uninstall the NVIDIA drivers and all of their components.
3) Now run Driver Sweeper. Select all NVIDIA, PHYSIX, ATI, AMD traces and delete them all.
4) Reboot your system and then download this(275.33 WHQL, do not use the latest beta or something else - this should be fine):

http://www.nvidia.com/object/win7-winvis...river.html

5) After installation reboot your system again. Make sure that in device manager your NVIDIA card appears and try launching the game again.

Also, make sure you check the troubleshooting thread, Problem B in your case:

http://www.frictionalgames.com/forum/thread-3754.html