Enable /Disable the (Hidden) Administrator Account on Windows 7, 8,8.1 or 10
Enable Administrator Account :-
Open Command Prompt
right-click on the command prompt icon in the Start menu or Start screen.
Now type the following command:
net user administrator /active:yes
You should see a message that the command completed successfully. Log out, and you’ll now see the Administrator account as a choice.
You are free to set password for this Account.
Disable Built-in Administrator Account :-
Type the following command:
net user administrator /active:no
The administrator account will now be disabled.