title: How do you get SQLServerExpress to create users?
body: <p>Running as Administrator on my machine, I can create databases just fine, but when I try to create a user it fails with this error message.</p>
  
  <pre><code>1&gt; create user mark from login mark
  2&gt; go
  Msg 15007, Level 16, State 1, Server ENDER\SQLEXPRESS, Line 1
  'mark' is not a valid login or you do not have permission.
  </code></pre>
  
  <p>I'm using sqlcmd to do this.</p>