I don't mean to be rude but I don't think your PC is high performance at all. 2 gigs of ram only? Most of my gamer friends are now working on 8 gigs. Only one video card? We're working from two to four video cards.

How long have you had your computer for? If you're using Windows, over time, it tends to start performing poorly. The regular checks like defragging and desktop cleanup work well. Spyware, malware and even background processes play a big part especially when dealing with a windows. :P

Don't hate me.