:Please kindly refer to below steps to check your system setting.
1.Please double check the onboard sound is working properly in Device Manager.
(If not, please reinstall Realtek HD Audio driver from Support CD.)
2.Enter the Sound setting in the Control Panel.
3.If the Default device of the Sound playback is "ATI HD Audio rear output", please change it to "Realtek HD Audio output".
4.Press "OK" to save setting.