If you have migrated a system to Vista which previously had a working SigmaTel audio driver installed on it, please use the following steps to uninstall it.
1. Select "Control Panel" from the Start button menu
2. Select "Uninstall a program"
3. Select "SigmaTel Audio" and click on "Uninstall". If "SigmaTel Audio" does not appear on this dialog, then go to the Alternative method section.
4. Select OK to confirm removing the previous SigmaTel Audio software.
5. The following dialog will appear while the software is being removed.
This will uninstall the previous SigmaTel audio device driver from your system.
You can now install an updated driver or reinstall the previously working driver.