the ram blows i thinks its only 533 mhz anf i had like around 70 proceses no virus thing no im only xfire and max was like 55 avg 35 min 25 i was like wtf!!
The factors slowing you down is 4gb ram and your CPU. Yea...definitely get a core 2 duo. Like fade2black2004 said....it does slow down your system, because windows xp can only handle 3gb. For optimal performance, stick with 2gb.
Thats true Vista can handle more ram. So I would take out 2gb leaving you 2gb left in your system and get a C2D. You could sell the 2gb or, save it for Vista.