Common Mistakes When Upgrading a Windows 2000 Domain To a Windows 2003 Domainhttp://blogs.technet.com/sheilarich/archive/2005/01/06/347742.aspxYou might want to bookmark this one, a single resource with lots of information. Before you "run" and upgrade system to Windows 2003 domain there are some considerations to take: http://support.microsoft.com/default.aspx?scid=kb;%5BLN%5D;555040&SD=tecen-USCommunityServer 2.1 SP1 (Build: 61025.2)