Just like its predecessor, Windows 8 has a hidden built-in administrator account. By default, this account is disabled. But if you have administrator access, turning it on is easy.
On the Metro Hom escreen, Type: lusrmgr.msc and press Enter. It’s a little strange at first, but that is how search works in the Metro UI. Just start typing and it automatically opens up.
Alternatively, if you’re on the desktop, you can press they Keyboard Shortcut Windows Key+ R on your keyboard to open the Run menu and type it in.
Lusrmgr (Local Users and Groups Manager Snap-in) comes up. Open the Users folder, then right click on Administrator and select Properties.
In the Administrator properties uncheck Account is Disabled. Click OK.
Done! The Windows 8 Administrator is now enabled and you can immediately sign in with it by logging out or switching accounts.