ok dumb it downing but please don't take offense then as none is meant.... your power supply (the thingy you plug your PC into the wall with...open you case panel (large metal plate on the side of your PC, usually has a fan or window) look at the power supply and look for a number next to wattage, give me that
second look at the mother board (big green or black square board everything is plugged into)...Do you see a long slot about half way down that has a little latch attached to it on the right hand side? If so that is your PCIe slot i mentioned.