You do not have a sound card installed on your machine, the sound card is not set up correctly, or another application is using the sound card
When I tried to play mp3 files, the player would play, but no sound would come out. I checked to make sure nothing was muted and volume levels were up. I can hear sound from other things and players such as AIM, Winamp, and real player, but not Windows media.
I've checked the device manager, and nothing was red or yellow. I even re installed the driver. I'm out of ideas now. Any ideas or advice would be appreciated.