ok seriously.......... there needs to be more info involved............
what OS are you running, how many processes are running in the background, when you say you pulled up your system information... by what means, what programs are running in the foregroun, how big is your video card, etc etc........ all of these things can change the reported free memory
for instance simply booting your machine in Windows XP (depending on installation, video card, setup, processes, programs opened, etc) can report a 4Gb machine with having as little as 3Gb or less available