"How to Enabled hidden administrator account"

Open the command prompt with administrator rights. So, press the windows key to open the metro interface and then and type Command prompt n the search box.


Type  net user administrator /active:yes Then, press enter  to enable your built-in administrator account.

to Disabled it 

Open the command prompt with administrator right and type this code net user administrator /active:noThen, press enter to disable your built-in administrator account.