When Windows signs you automatically in to desktop, open an elevated Command Prompt and enter the following command to reset your password:
net user Username Password
Replace Username in above command with your local account username, and Password with you preferred new password (Microsoft account passwords should only be changed on https://account.live.com).
Example: Windows local user account username JohnDoe wants to reset the password to MyNewPassword123, the command would be:
net user JohnDoe MyNewPassword123
Sign out from Windows, sign back in. Now you can remove the automatic sign in.