Well number one, the Xbox has somewaht better specs then your rig, with maybe less memory. Sure if you want to play DVD's, you can get an ATI card, that shoudl help with DVD playback, hopefully your system can take it. But if you want to record live TV with a software card, again your computer may be able to do it, but you would not be able to do anythign else at all whiel its recording and then you still might get dropped frames, and software cards don't offer the highest picture quality.