I have an Athlon 2.4ghz pc running Windows XP Pro with a Gigabyte M57SLI-S4 AM2 NFORCE 570 mobo, with 2gb ram. I recently purchased (cheap!) 2gb from a friend who was tearing down his old PC and decided to install them in my system. Yeah, I know 4gb is overkill, but I have it, so why not? Anyway, I installed both chips, but my pc is only showing 3.25gb ram, instead of 4gb. Why? I know the max ram for my mobo is 4gb, so that shouldn't be a problem. Suggestions?