If you are using a WDM (Windows Driver Model) audio driver, and you use special keybaord keys to adjust audio properties, or you use FN+PAGE UP (increase volume), FN+PAGE DOWN (decrease volume), or FN+END (mute), These settings are NOT saved in the registry.

If you have the Volume Control open when you perform these actions, you can see the Volume Control slider change?

To workaround this problem, double-click the Volume icon, located on the taskbar, and use it adjust the appropriate volume settings. When you exit the Volume Control tool, your settings will be saved.