What is the make and model of your computer?
First, run the Playing audio troubleshoot - open Start > Settings > Update & security > Troubleshoot
Scroll down, select Playing audio
Click Run the troubleshooter
When complete, restart your computer then check if audio is working again.
Press Windows key + X
Click Device Manager
Expand Sound, video and game controllers
Right click your audio adapter
Click Properties
Click the Driver tab
Is there an option rollback?
If so, click it.
Open Start, type: change sound card
Select the Playback
Right click your Speakers
Click Set as Default Device if it isn't already
Select your speakers
Click Properties
Click the Levels tab
Use the slider to adjust level