PCUnlocker
Windows Live Sync
Simply because you are able to change your Microsoft password from ANY computer while your W10 computer is turned off or offline, means that the two can get out of sync. That the two can and often are different is not a unique problem. I have tried the last few "online" passwords and none are a match, so obviously the process that syncs the two passwords has not happened for some time. Very frustrating.
Option One: Enable or Disable Built-in Administrator in Elevated Command Prompt Option Two: Enable or Disable Built-in Administrator in Local Users and Groups Option Three: Enable or Disable Built-in Administrator in Local Security Policy Option Four: Enable or Disable Built-in Administrator in Command Prompt at Boot
http://www.tenforums.com/tutorials/2969-administrator-account-enable-disable-windows-10-a.html