Make a Restore Point.
Start - type in --> Restore ......find at top can click on it - Create.
Right Click the Start Button - Device Manager - Sound, Video and Game controllers - double-click the Conexant sound drivers - Drivers tab - Update drivers -OK then go back to the same place and Uninstall - OK - when done restart the computer - that refreshes the driver stack.
Now update or reinstall the sound/audio drivers from your system or motherboard maker's site - such as Lenovo, Dell, or others.
That should restore the sound and the Sound Control Panel.