Hi guys,
you can repair it in 2 ways, one is simple just reinstal realtek sound drivers and the other is to change your settings in realtek.

1. click start button > control panel > Hardware and Sound > Realtek HD Audio Menager > Device Advanced settings ( in the right top corner) and select second option ( Make front and rear output devices playback two different streams simultaneously) and your done !

hope it will help you as it worked for me