It sounds like there is something wrong with your sound card driver, you need to reinstall it.
1 . Press the Windows Key (to the left of the space bar) and the Pause break key at the same time. This will launch your system properties. Or you can get there by going to START, SETTINGS, CONTROL PANEL, and the select SYSTEM PROPERTIES.
2. Go to your DEVICE MANAGER tab and look for any item with a red exclamation point in front of it. If there are any, highlight that item and then right click and select properties.
3. Once you are in the properties for that device, Click on the button that says reinstall driver or update driver.
4. If there are no red exclamation points in your DEVICE MANAGER, I would update your sound card driver using the steps above. You may need to download the newest driver for your sound card from the manufacturer, your Device Manager will tell you what card it is and you can go to the makers site and obtain it.
If that doesnt work or you have more questions, just ask.