K you guys have it all wrong. halo 2 pc wont be able to play halo 2 xbox. But their si hope for other games. In the new opperating system VISTA. they will have an ability to do croos platform. So if you have seen those games that say games for windows their going to change the requirments. For a game to be games for windows it has to have the ability to pllay against people who own an xbox.

So their will be an xbox live for pc and xbox.