32 bit versions of windows can only adresss 4gb of memory including your system ram, your from from your videcard, and your ram instaled in your mobo, if you do some math u will realize the following = 4GB RAM - 512*2 RAM( your 2 videocards) - Memory on your mobo - Memory on your CPU = do the math and thats like -3GB ram, remove one Video card and your ram will increase. sorry for my english xD.