Originally Posted by Nite
no you can't, Windows Live and Xbox Live are seperate networks.
I don't think we will ever see the day where console/PC gamers can play on the same network.
as far as game mods I'm not sure.
No, they are the same network. GfW Live is essentially Xbox LIVE. I got my GamerTag linked to Games for Windows Live, it's the same network. My Halo 2 PC scores I recorded onto the Xbox LIVE gamertag, and so are my Xbox 360 game scores. They all contribute to one total score which is the gamerscore.