[Nadia]

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!

Just bought a laptop 4G Ram with Windows 7; internal descript says 2,99G ram available. System (OP 32bits) need/uses 1,01G of ram. Vendor also told me,
that Windows XP sys was using A LOT LESS then that.

Have an old comp with 1G ram and XP, which could be expended to 2G, However doubling the RAM would only get me 1,5G addressed by it's Pentium4 processors.
Having the slot doesn't mean the hardware can handle it. Check SPECS.