Follow these troubleshooting guide if Windows Taskbar icons or buttons not working. You will have to restart explorer or run these commands.

Fix invisible Taskbar icons issue. If they are not showing or disappear & reappear randomly, go missing or blank or get blanked out randomly, see this post.

Right-click the sound icon from the taskbar and choose Sound settings. From the Output area at the top, select the small circle next to the device you want to hear sound through.

I hate most icons and such, I'm the type who unchecks "show desktop icons". The sound control in the taskbar is pissin me off, and I don't know how to get it off. Can somebody help me out?

A. You can make the sound icon visible on the taskbar by going to Control Panel, double-clicking Multimedia, selecting the Audio tab and then checking the "Show volume control on the taskbar" option.