As delivered out-of-the-box, Mac OS X does not enable the ROOT account. Upon first BOOT, you create a user account & password and then set the Admin password. But that is not the same as becoming ROOT. Sometimes, changing a config option or adding a control file needs to be able to "su root". First, activate ROOT by: Click the lock in the Directory Utility window. Enter an administrator account name and password, then click OK. Choose Enable Root User from the Edit menu. Enter the root password you wish to use in both the Password and Verify fields, then click OK. Pick a good password as this account is well known and only your firewall & this password will protect the account.