title: Enable sys, guest and information_schema users in SQL Server
body: <p>I had a script run against one of my databases that attempted to drop a bunch of users.  All the users that had the drop attempted against them were disabled and displayed the little red down arrow on their icon in Management Studio.</p>
  
  <p>I was able to revive all of the normal users by issuing the "alter login <em>myLogin</em> enable" command.  However, when I try to do that against the sys, guest or information_schema users, I get the "Cannot alter the login '<em>myLogin</em>', because it does not exist or you do not have permission.  I'm logged in as a system administrator.</p>
  
  <p>How do I enable these accounts?</p>