This is another archived fix for future reference, if anyone comes across with a similar problem.

GRAW worked fine on XP. But when I installed Vista, I was getting a MAX of 5fps, and only when I was looking at the ground. Frustrating. So after a long while of searching I eventually found an interesting fix.

GRAW Vista low FPS fix

While this may not work 100% in all cases, this did definitely solve all of the issues I was having. After applying the necessary changes and switching my speaker settings from 5.1 to stereo(out of game), it works fine.