To restore sound to computer speakers, make sure the speakers are plugged into the computer and that the power is connected, then run the troubleshooting feature for the audio component of the computer and update any necessary drivers. There are several reasons why sound might be disabled on a computer or through the speakers, so rule out possible causes until the correct source of the problem is found. If the speakers are accidentally disconnected from the computer, or if the power is turned off, the speakers will not emit any sound. Additionally, if the volume is muted on the computer, the user can restore it by clicking on the volume icon in the toolbar at the bottom of the Windows screen.
Troubleshoot the audio system
Click on the Start button, select the Control Panel and type the word "audio" into the search box at the top left of the dialog. Hit the Enter key, then select "Find and fix audio playback problems." The troubleshooter will alert the user to any problems that might exist with the audio system, then attempt to fix them automatically.
Update the sound drivers
Running a driver management tool on the computer helps identify outdated or missing sound drivers that could result in a lack of sound from the speakers. Alternatively, the user can update sound drivers manually by opening the Device Manager from the Control Panel, then clicking on "Sound, video and game controllers." Visit the sound card manufacturer's website, then search for the appropriate drivers based on the sound card model number listed in the Device Manager.