The problem may be caused by improper audio setting. To check the settings of Recording Control, carry out the following procedures:
1) Click [Start]->[Programs]->[Accessories]->[Entertainment]->[Volume Control].
2) In [Volume Control] window, click [Options] and select [Properties].
3) Choose [Recording] under [Adjust volume for].
4) Make sure the [Line], [Microphone], or [CD Audio] boxes are checked and click the [OK] button.
5) In the [Recording Control] window, check the [Select] box accordingly to enable the device to record sound. The volume can be adjusted by adjusting the scroll bar.
6) Close the [Recording Control] window by clicking [Options] and select [Exit].