Menu when Righ-Click on “Start” Button

Normally, when you right-click on the Start button, you get a short menu with 3 options: “Open”, “Explore”, and “Find”.
Somehow, “Open” and “Explore” are now greyed out.
I don’t know how to identify that menu in Regedit, so that I can try to fix it.
Any ideas?

Thanks for any help,
bccomp