Slow window movement while dragging and scrolling

OK, I recently reformatted my hard drive completely, and did an upgrade to Windows XP Pro. My computer as a whole is working great, but I notice a lot of lag. Like when I drag a window, it is very slow and lags. Another problem is that when I am in any browser, whether FireFox or Photoshop, it scrolls very slowly. It also had a sort of lag to it. I don’t really know how to explain it much better, but it’s sort of like im on a dial-up trying to play a highspeed internet game, but it’s acting like that all the time. I don’t think it’s my screen refresh rate, because my mouse cursor moves very fluently.

Any assistance would be greatly appreciated. :beam: