http://blogs.msdn.com/lcris/archive/2007/10/25/basic-sql-server-security-concepts-sids-orphaned-users-and-loginless-users.aspxI am grouping here two topics (orphaned users and loginless users) that are actually very different, but I have often seen confusion between them, so I am covering them together in an attempt to dispel that confusion. In a previous discussion of loginsen-USCommunityServer 2.1 SP1 (Build: 61025.2)