Quick fix if your volume icon stops working erratically like mine does in Windows 10. Still waiting for the day Microsoft fixes this (happens only in Win 10, did not happen before).
- Open Task Manager. If you don’t know how, click on your Windows Start Menu then type “Task Manager.”
- Scroll right down to the bottom past Windows Processes to “Windows Explorer.”
- Right-click, select “Restart.
- PROFIT! You can now select your sound output (headphones vs monitor, etc) and change your volume.
You’d think they would have fixed it by now, but as this thread shows, it’s still happening today. Sigh.