A motherboard needs a proper bios to support different processors. Assuming your friend knows what he is doing, if he says you can't , then you probably can't just drop in a quad core CPU - although most motherboards that support dual core will support quad core with the proper bios. Assuming he built it properly, you wouldn't need anything else.
You can look stuff like this up yourself. Just find the motherboard model # and go to the manufacturer website and see the list of supported CPU's
You can look stuff like this up yourself. Just find the motherboard model # and go to the manufacturer website and see the list of supported CPU's
