Rear speakers not working

[Dexterqo]

Hello, I'm installed the Windows 7 and Realtek sound driver.
Front PC speakers works good, but rear speakers not working. If I use Test device the speakers plays test music, all speakers works good. But if I play mp3 in winamp or windows media player works only front 2 speakers. Please help me.
PS: Sorry for my bad english..







In test working all 4 speakers.. in winamp, wmp working only 2 front speakers

 

[modelt]

Seems like common problem, some have worked around it some cannot

Check this http://www.sevenforums.com/sound-audio/1991-windows-7-5-1-surround-problems-realtek-4.html