The only way to get TOTAL use out of 4gigs of memory, is if you upgrade to windows x64 or simiair OS. Keep in mind, however, that over 80% of average programs in x64 will be emulated in WOWx32. Truthfully, unless your runing a strenuous. program like Auto Cad theres no way you could see gains with that much RAM over 2GB.(vitural systems maybe) Most programs out right now are not even designed to use it. So unless you are a Graphic Designer, Arcitech, or an extreme multitasker, your wasting your money. Sure you could buy it now with hopes that youll use it for vista or in the future, but chances are by the time this comes around you could pay about half the price for the same memory upgrade.