When you start Flight, you get the following error:
LIVE gaming on Windows failed to initialize. This may be because another LIVE Gaming on Windows application (such as Halo2 dedicated server) is running on the same machine. Otherwise, reinstalling the game may fix the problem.
If this did not fix the error, see the following article for more help:
When you try to load a Games for Windows – LIVE game, you receive one of the following error messages: "System Cannot Find the Path Specified" or "LIVE gaming on Windows failed to initialize"