I would assume this is a common, easily fixed problem. However, my knowledge of computers is fairly weak as I've always had tech friends fix my problems.
When I load up Fable 3 via steam and log in to windows live, I recieve an error,
"The LIVE service my be unavailable, or there may be an issue with your home network equipment or firewall, etc"
I've searched through some threads and they mentioned something about UpNP, but once again I have no idea.