Hi. My name is***** you for your question and the opportunity to assist.
Can you tell me which version of Windows you are using?
Thank you. Click in the search box and type: find and fix
and open the search result.
In the upper left of the window click View All
You'll see a list of troubleshooters.
Run the Playing Audio troubleshooter.
What is the brand and model of your computer and how long ago did the sound loss happen?
There can be many reasons why your sound went out and I have to know details in order to help you.
If the sound was working recently and suddenly stopped you can try to set the system back to the state
it was in when the sound was working. To do that, right-click on the start menu button and select Run.
The Run box will open.
In the text area type: rstrui and click OK
System Restore will open.
Click Next and put a checkmark in the box labeled "Show more restore points" (if visible)
Restore points are time stamped.
Select a restore date when your sound was working and click Next, then Finish.
When the restore is complete and the computer restarted check if you now have sound.