Hi i am new here and am an amateur computer builder. I have completely striped down a computer and put it back together and was wondering something. I have an older Compaq Presario SR1503WM. Currently it has 256MB of DDR ram, i am going to max it out at 2GB. I know i have to purchase a DDR graphics card unless i update the mother board. I want to upgrade the CPU to a Duel core but have pulled one out of another computer and realized THERE ARE TWO DIFFERENT KINDS. Mine has the little prongs on the bottom while this one is smooth. If i want to upgrade mine what kind would i have to get. Or do i have to upgrade the entire mother board. Please help i am so clueless on compatibility on these things.