My motherboard only sees 3.4gb of the 4gb installed, motherboard is a gigabyte ga-73vm-s2 cpu is an Intel core 2 quad q6600 ram is 2x2gb ddr2 800, I do a lot of refurbs on older systems, give them upgrades and sell them for cheap, but I can't sell this one if there is something wrong with it, I've been all through the bios, and have disabled the onboard graphics, I've messed with the memory settings, but can't get it to see the full 4gb, I've also used different ram, and the same result, any help would be greatly appreciated.