It sounds as if you need the audio drivers.
You can download the drivers from Acer.
Start HERE:Acer Support
Choose the product, then the product line, then the model.
When the Operating System box shows, look just below that to the line Operating System. Use the drop-down arrow to choose your OS.
Below the boxes you will see Audio. Download and install the drivers.
Edited by Queen-Evie, 28 August 2010 - 07:51 AM.