I was runing a single query testing DTA, tha's what I find: 1) Using sql 2000 sp4 never ends. 2) Using sql 2005 sp2 works fine. Both instances are in the same server with Windows 2003. I already post this problem in Microsoft forum. Luis Martin Moderator SQL-Server-Performance.com All in Love is Fair Stevie Wonder All postings are provided â€œAS ISâ€ with no warranties for accuracy.