I currently have a Core 2 Duo processor, but the XP is my brother's. The only games it has to be capable of playing would be like Zoo Tycoon 2, Rappelz, and maybe Guild Wars. He won't be playing any of those graphics-intensive games. Since right now he has integrated graphics, I'm upgrading it to an AGP 8x 6600GT and RAM to 1GB if possible. Will that be enough?