maybe it is the ram
im on vista also, 4gb ram, sometimes when gaming it eats up
78precent of my 4gb
another things is the graphics card, maybe you need a faster
one, are u a gamer? do you play grahpics intensive games? if yes,
maybe you should get a 9800gx2
if light gamer, get the 9600gt
Weather you are a heavy or light gamer, as long as you are
a gamer, I suggest you "Upgrade" to Windows XP for the
performance. Except for the Aero Glass, Flip 3D etc., I
don't see how Vista can be better than XP. Vista has many
unnecassary things running in the background like user
account control which hogs the CPU and RAM. If you need
DirectX 10, there are hacks for you to install DirectX 10 into
Windows XP.