WMA is an audio format. Do you mean WMP - Windows media player?
* Does a reboot make any difference?
* Do you have the latest audio driver installed? click here to d'load (assuming your using Win2K/XP). If you have, uninstall/reinstall them.
* Have you tried an alternative media player? Quintessential Player click here (2.17Mb) / Winamp click here (0.93-5.79Mb) / Jet Audio click here (15.6Mb) / Musicmatch Jukebox click here (26.3Mb) / RealPlayer click here (8.15Mb).