[Multimetal]

Hi all, I just upgraded my PC with 2x2GB sticks of Corsair ram, and when I check my system properties in the Control Panel it says I only have 3gb of RAM. I'm running Athlon X64 5400 dual core processors @2.81Ghz on a Gigabyte MB, Windows XP SP2. I replaced my original 2x512 sticks with the new RAM. When I boot up, the BIOS recognizes 4gb of ram, so maybe this is an issue with Windows? I'm not the most computer-savvy guy in the world, so any help would be appreciated, thanks!