Ohh... it's onboard video card. It’s going to be very educational for you.

What I'm suggesting you to buy a recommend level graphic card - NVIDIA GeForce 8800+. It might will work on your PC without buying a new power supply. Or you can call HP and ask what they recommend what graphic card that your PC can handle.

One more thing, if you buy a graphic card and install on your PC - you will need to disable onboard video card (through BIO setup) in order to make the new graphic card work.