STEP 1:
WINDOWS + I (settings)
-> ACCOUNTS
-> SIGN-IN OPTIONS
turn OFF "Require Windows Hello sign-in for Microsoft accounts"
close the settings window (changes are saved automatically)
STEP 2:
launch a CMD prompt AS administrator
run " netplwiz "
You should now get a "USER ACCOUNT" window
UNselect the option "Users must enter user name and password...." (the change above in the accounts makes this option visible)
Click APPLY
You'll be asked to give a user name and password.
Put in the username and password for the main account for this machine
Press APPLY
Reboot!