Registry key to reset Windows 11 taskbar.

Copilot

I believe you are referring to the Taskbar. The registry location of the Taskbar is

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Taskband

1st back up this key
then favourite the root key 

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\

then delete it 

\Taskband

I hope this helps!