If your computer is experiencing an error where the Windows Security icon disappears from the Taskbar, please refer to the ...

The simplified Windows 11 system tray design was close to being launched, but Microsoft backed out at the last minute.

If you press the key combination Alt-Shift-Esc or right-click an empty area in the taskbar, you can launch the Task Manager ...

As uncovered by PhantomOfEarth in a beta build of Windows 11 (22635), there's going to be an option to have the taskbar icons made smaller - but this is hidden in the preview right now.