Hi. I'm new to the whole upgrading thing. I want to upgrade my video card but have no clue what kind to get. Just looking for something that will run Call of Duty World at War. PCI, PCI express? My computer model is an HP a6000n. thank you in advance for any input..(oh yeah ive upgraded my RAM to 2GB but the game still runs unbearably choppy. i assume its the video card that sucks) thanx