We can't sign you into your account

This is a bummer! Or, I am a bummer. I staarted up the Admin account, and it wouldn't sign in. Then, I guess because of the changes I made in the registry, I can't sign in to my normal account. The name is there, the pin is accepted. But rather than saying "Welcome", I'm getting :Preparing Windows". then I get "We can't sign you into your account". It says I need to sign out and sign back in. The Admin account is not accepting the password I created for it. WHAT NOW???

Brink, I'm not exactly sure where my train went off the rails, but everything was fine until I signed out in order to sign in with the new Administrator account. I did all of the preceding steps, and got to the sign out/sign-in, and the password I made for the Admin account, in cmd/elevated, didn't work. So, I tried to login again with my Microsoft account, I got the dreaded "We can't log you into your account. Often, this can be fixed by signing out, and signing back in. No files will be saved under this temporary account"..., or words to that effect. And now, every time I log out and back in, I have to reset all of my UI settings. This is a horror movie! I got so much stuff that trying to remember what I had will be a nightmare. But it's a nightmare of my own making. Is there a solution to going back to what I had, in full, and not have to reset/reinstall Windows?