Thanks for the tip Bob but in the last sentence I wrote that the sound on the computer is all the way up. The only thing that seems to work is to restart the computer but that only works about 1 out of 4 tries.
I suggested he uninstall the program and then reinstall. I also suggested that he call the Real Flight people and see if they have any suggestions. I hate playing it with no sound. Its like being deaf. Or flying an electric.
His sons friend just hit the "M" on the keyboard to unmute. Of course I tried that. I spent an hour with it and couldn't get it to work. And I am normally pretty good on computers unless it gets too deep. But keep any suggestions coming.