for some reason i can only run NV (well) on low quality even though my PC well exceeds the minimum requirements.

i am running windows 7 home premium (64 bit Opp) with 6GB of RAM. My Graphics card is a ATI Mobility Radeon HD 5850.
if anyone can help me figure out how to fix this i would be very grateful.

im sure you have probably already looked into these simple problems but i mean just in case.

Check the temperature make sure it's not over heating, update drivers, dust inside, restart computer

I do apologize for the simple solutions but i thought it couldnt hurt incase you overlooked something.

There are tons of nonsensical performance and technical issues - sound issues, white flashes of light randomly appearing on the screen etc. The game needs some serious debugging. Systems that run games like Bad Company 2 and Crysis on max settings with ease are crapping out with the comparatively simple graphics in this game.