I am part of a hospital affiliation where I have a forest with one domain and the mothership has a forest with multiple domains, including exchange 2003. We need to move our domain (which currently has 2 DC running AD) to the other forest (motherships) applications in our domain rely on the AD of our domain for users/groups/security. We are hospital, downtime needs to be minimal so reinstall of apps could be a "resume generating event" What is our best way to handle this? My thought was to bring up a new dummy DC up in the current domain, enable the GC. Create a new domain under motherships forest. Recreate users/groups/security in new domain. One by one move all servers to new domain. Demote all DC's except new dummy DC to member servers. Move these member servers to new domain. Move all workstations to new domain. Test all thru this process. Once everything is moved to new domain/forest, reinstall dummy DC and move to new domain/forest. Is this possible? What tools would assist me? What roadblocks will I face? What am I missing? Any feedback would be very much appreciated.