How to Edit Volume in the Registry
In Microsoft Windows operating systems, administrative users have the ability to enable, disable and modify numerous functions that affect the system's behavior. The Windows Registry Editor makes these modifications possible. One of the many settings users can modify from the registry editor is the system sound (volume). If desired, the volume settings in the registry can be changed from on to off. This is a simple modification, but it will affect all the computer's users if changed.
Open the Microsoft Windows Registry Editor by going to Start > Run, typing "regedit" in the search box and clicking "OK".
Open the Volume registry key by using the left navigation pane to go to Computer > HKEY_CURRENT_USER > Control Panel > Sound.
Edit your Volume settings. To turn sound on, double-click on "Beep", set the data value to "yes", double-click on "ExtendedSounds" and set the data value to "yes". To turn the sound off, set the value data for both these keys to "no".