title: Cannot perform a differential backup for database "ABC", because a current database backup does not exist
body: <p>Im trying to take differential back up on sql 2005 server with SP4 (Workgroup Edition) but it gives me below error...</p>
  
  <pre>
  Msg 3035, Level 16, State 1, Line 1
  Cannot perform a differential backup for database "ABC", because a current database backup does not exist. 
  Perform a full database backup by reissuing BACKUP DATABASE, omitting the WITH DIFFERENTIAL option. 
  Msg 3013, Level 16, State 1, Line 1
  BACKUP DATABASE is terminating abnormally.
  </pre>
  
  <p>Fullbackup exists but its still giving above message. I found <a href="http://support.microsoft.com/kb/921106" rel="nofollow">this article</a> but it seems this is applicable for sql server 2005 with no service pack.</p>
  
  <p>I got below error when I tried to install above hotfix.</p>
  
  <blockquote>
    <p>This update requires service pack 0. The service pack for product instance MSSQLSERVER is 4.Download the update for service pack 4.</p>
  </blockquote>