Cannot use Start Menu and task bar

I’m using Windows 10.

I have two user. I know from lusrmgr.msc that built-in administrator belongs to the Administrator group.

When I use the built-in administrator and click the Start Menu or any other button on the task bar, or use the keyboard’s Start button, nothing happens.

But when I switch to other user or create a new one, everything works perfectly.

So there’s clearly something wrong with the user. How can I debug that ?

What I’ve tried:

  • reboot