Windows XP 10

Recently, my windows media player 9 just stopped playing music over the
speakers. It appears that everything is working, time goes by, it can be
stopped, paused, etc., the music simply will not play through the speakers.
I then downloaded XP 10 to see if it would help, but it did the same thing.
Any one know why or how to correct this situation? My Real One player is
having no problems playing through the speakers, though, so it is not a
hardware problem.