- last post: 01.01.0001 12:00 AM PDT
I can only speak for Halo 2 Vista, although I would assume any PC game that has the 'Live' branding works the same: Yes, you can use your Live account from XBL in your Live-enabled game. You can send/receive messages. I'm not sure if voice chat works, but it might.
There's even a 'dashboard'-esque menu that you can enter by pressing 'Home' on your keyboard (or the 'Xbox' button on a 360 Controller plugged into your PC).
Live gives you features, but requires you to pay for multiplayer, just like on a 360.