For 80% sure it’s your motherboard, but you already gave that answer your self. There are nice setups that you could think of with onboard VGA, PCI-E and DDR1 RAM. I would go for a motherboard with a nVidia nForce6100/6150 and a Sempron64 for budget. If you could sell you RAM I would by an AM2 motherboard and some DDR2 667/800 with a Sempron64 so you could upgrade later to a X2 CPU. If money isn’t an issue and you like to get the newest stuff that runs great for 32bit apps then go with JuMz, but the market is still new for the Core 2 Duo, Intel is having his new chipset with onboard VGA released soon (if they already did and they say it´s with DX10 support). I hope this helps. EDIT: I´m sure you are looking for budget, else you already would have had a VGA card .