If Windows 11/10 Taskbar Volume Control icon has stopped working & when you click on the volume icon nothing happens & you are not able to change the volume see this post.

Change Default Sound Output Device: Speakers, Headphones, Bluetooth headset in Windows 11/10, using Volume Taskbar icon, Settings, Control Panel or Game Bar ...

What OS? <BR>In 2000 go to control panel, sounds, and uncheck "show volume icon in taskbar"<BR>In XP right click on taskbar, click customize, then change to always hide.

Of course, savvy users know that you can add an entire iTunes toolbar to the taskbar in both Windows 7 and Vista, but that just adds clutter.