Hello
In this case follw the follwing steps:
1). First check the device manager. If there is some yellow ? on the Audio controllers or options like this. Then you need to install the driver. If this is the case .....reply me.
2). If drivers are there......then download the codecs for the windows Media player 11. Plz click on the follwing link to download the codec:
http://www.free-codecs.com/download/BoliGego_Codec_Manager.htm and then install it.
3). Restart the computer. I am sure it should work. Reply me if the issue still persists.
Regards
Himanshu Dogra
MCSE