I am in the process of planning and designing a large migration from WIN NT 4.0 to WIN 2003 AD. Our current AD domain is in place and has been for some time because users in the NT 4.0 domain authenticate to AD for web based time entry and web access. Therefore, all the users in all NT.4.0 domains have user accounts in AD. There are about 50 NT 4.0 domains. I’m confused about how to migrate. I don’t want to migrate the NT accounts into AD because they are already there. But, I’ll need to migrate user profiles and computers etc. Is it possible to migrate only the SID’s or somehow associate the NT 4.0 account SID’s with their matching user account in AD? Or does anyone have any thoughts on the best way to approach this?