Many users have posted an issue related to the volume / audio icon not working when clicking on it. If you are also a victim of this error, here is a working solution to fix this problem.
Solution 1: restart File Explorer
1. Press Ctrl + Shift + Esc to open the Task Manager.
2. Now find Windows Explorer, Right click on it and choose Final task
3. Go to File> Run New Task
4. Write explorer.exe on it and click ok.
Solution 2: fix audio problems
1. Press Tasto Windows + I together to open settings.
2. Click Update and security
3. Click Solve problems
4. Expand Play audio by clicking on it.
5. Click Run the troubleshooter
Fix 4 - Add new user
1. Press Tasto Windows + I together to open settings.
2. Click Accounts.
3. Click Family and other users from the left menu.
4. Click Add someone else to this PC
5. Log out.
6. Log in with a newly created user account
