Thanks for the replies. I bought a 4 gig OCZ stick to give it a try and as you stated I don't see much difference in Vista performance. I am running 2 gigs of Corsair XMS in my system. I am getting ready to upgrade this system with a new mainboard , CPU and ram.

http://www.newegg.com/Product/Produc...82E16819103272
http://www.newegg.com/Product/Produc...82E16820145197
http://www.newegg.com/Product/Produc...82E16813131339

I have Asus Nforce 4 sli mainboard now with dual gfx cards and a 4400x2 cpu. Are the parts listed above worth the effort. Or would a quad core be better? My system runs pretty sweet now so I am not wanting to waste money. I do some gaming and watch movies ect... Just wondering if the jump to am2 and DDR2 is worth it. Thanks