II. ONLINE PLAY
Q: Is it possible to play online with people who have other versions of Chessmaster?
A: No. Due to the use of different protocols, you can only play against others who are using Chessmaster Grandmaster Edition.
The Playchess server, on the other hand, permits players with any version of Fritz or associated software to play in the same environment. Chessmaster's online play is not worth talking about. As a practical matter for the serious player, it does not exist.
Also see my "Chessmaster vs. Fritz: Analysis".