What is this "feature" and how do I get rid of it?

I just rebooted my computer (updated to W10 about 2 weeks ago), and now all of the sudden it wants me to enter a password, for some kind of Microsoft account – this is before I can get to my desktop. They do cleverly tell you how to reset the password at live.com, and I do seem to have some kind of account there, which has something to do with having asked a question on a MS support website (9 months ago), or more probably because I recently Googled a technical problem and the answer, available at an MS webpage, required me to login using my "Microsoft account".

I really do not want to have to log in to an MS account every time I boot up -- I'm willing to stop using MS information pages if that's the price. I cannot figure out how I got into this forced-login situation. Nothing obvious shows up in the Startup option of Task Manager. Under "Accounts" for require sign-in, it says "never".

There are untested options. Under Accounts-Email and Accounts, I might click "Manage my Microsoft account"; it tells me I need to verify my identity on the machine and gives me an option to do so; I have the option to sign in with a local account. I might change the password or set a PIN. But since I have no idea what these things do and there is a reasonable chance that by initiation one of these processes I will be forced to do something else, I'm rather reluctant to do any experimenting.

What I want is that it stops forcing me to log in to some Microsoft account. Is there any way to do this?

Login in local or Microsoft account:

Local Account or Microsoft Account - How to Tell in Windows 10 - Windows 10 Forums

Thanks; I tried to change to a local account but it insisted that I supply an account name (reasonable) and wouldn't accept my existing account name since it was "in use". Rather than play around with making a temporary bogus administrator account and trying to dig out later, I opted to do a system restore, which undid the damage. I still have no idea how this happened, but maybe I will get lucky and it won't arise again.