When users try to log in Windows 10 with Microsoft account or local account, they probably encounter difficulties as Windows 10 does not accept password after upgrade, for various reasons, like system compatibility, etc. Excellent as it is, recently many users complain about the problem that 'Windows 10 won't let me sign in'. Windows 10 offers you marvelous user experience, no matter for its performance as well as look. I signed out of other computers I'm on and tried again. This problem can be often fixed by signing out of your account and signing back in.' That's puzzling right there, because I haven't signed in yet.
Then it says 'We can't sign into your account. When I log in with my PIN, it first says 'Preparing Windows.' which it never did before. Then the problems began when I tried booting up again. First I couldn't get the computer to power down, so I did it the hard way with the power button. 'This all started after a Windows update.