How to Enable the Root User in Mac OS X

Enabling the Root User Account

Ready to turn on your Mac's superuser account? Here’s how to enable the root user account in Mac OS X and set the password:

1. From the Apple menu, select System Preferences.
   
2. Select Users & Groups.
   
3. Click the lock and authenticate with an administrator account.
   
4. Select Login Options.
   
5. Click Join, as shown in the figure below. 

6. Click Open Directory Utility. The Directory Utility window appears.
   
7. Click the lock and authenticate with an administrator account.
   
8. From the Edit menu, select Enable Root User.
   
9. Enter the password for the root user in the Password and Verify fields.
   
10. Click OK to enable the root user and save the password.
    

Logging in as Root

Now you can log in as the root user at the Mac OS X login screen. When the list of users appears, click Other, type root in the Name field, and enter your root password in the password field. You'll be logged in as root until you log out, restart, or shut down your computer.
Note: To log in as root from the OS X login screen, you must have automatic login and FileVault disabled.