Need Halp! Game runs very SLuggish!!

Here are my PC specs,

Windows 7 64bit
AMD Phenom(tm) II X6 1035T Processor(6 CPUs) ~2.6ghz
8G RaM
ATI Radeon HD 5700 Series
1680 x 1050 (32 bit) (60Hz)
ASUSTek CG1330

I've tried switching around with window and full screen mode, lower/uping graphic settings. No sound/sound. Turned off all shadows. Cleaned out inside of computer. No software updates for graphics card that I could find needed. I'm at a loss for why this is happening to me.
Any help would be greatly appreciated thanks!!!!!