How to Un-Mute Your Computer
The Window's volume mixer is the operating system's default volume control. This tool can mute and un-mute audio as well as adjust the individual volumes of programs and external hardware. If your computer is not producing any sound, Windows may have the audio output muted. Changing the volume control's settings is simple and can be done from the desktop of your computer.
Right-click on the speaker icon on the bottom right of your screen.
Select "Open Volume Mixer" from the top of the drop-down menu.
Click the small speaker icon underneath the speaker logo. This will un-mute the speakers of your computer.