Removing the Guest User

That is correct, the Guest User account is not removable.

That said, unchecking the Allow guests to log into this computer, disables access to login as a guest and therefore the person logging must use a known user account and password. It is a security measure.

To your MacBook, what version of MacOS is it on? Also, I suspect the single account you have setup is an Admin account and not a Standard User (if you check Users & Groups in System Preferences, I suspect it is there).

Cheers,

Anthony

OK now I think I see what the problem is. The upgrade may have changed the "Display login window" choice.

Go to the Preference, select Login Options, check "Name and Password" instead of "List of Users" and test.

If that doesn't help, startup in Safe Mode follow by a normal startup, re-visit the settings and test.

Your item #3 if unchecked should remove the guest user from your startup screen. I tested it on my M1 and that works.

This image doesn't resemble the Login screen on my Catalina Macs.

Neither is that the standard Catalina response for a Guest User login.

Something is different about your Catalina OS. What is it?

Is this Mac being managed by an employer's IT dept or other group? It may explain why you're chasing your tail here.

If you look in System Preferences do you see a selection called Profiles?

If the Guest User is Off, then there is nothing to do or worry about.

It will not show up at Startup and no one will be able to use it.

Re-visit/re-check the preference settings, after Safe Mode and normal Restart.

No one here can answer "why" Apple has made a specific interface choice.

It's not clear what you mean by "When I click on guest user it suggest to run in safe mode any way." Guest user and safe mode aren't directly related. Safe mode is a diagnostic mode. To me, it sounds as if there may be something else going on.

What is your concern with having Guest User on your computer?

Hi,

we are not Apple and are just, as you, public users. You might want to contact Apple Support to ask you question off, as they can look into is. The Apple Support link is in the upper right quadrant of this page.