i have installed windows XP pro on an amd X2 computer, i have also put in 4GB of DDR in the system but windows in the system properties only sees 3gb the bios sees 4gb. and im just wondering if there is a limit in XP or someway that i can get it to change to show the 4gb because i want to sell this system. interestingly enough. i will run a belarc on the system and it shows 3072 of total but then lists 4 banks of 1gb modules of ddr. odd memtest also sees 4gb and i have run a total of 28 passes on it with no errors. does anyone know how i can get windows XP to display 4GB DDR?