Hi I have an infrastructure that requires a migration from exchange 2003 to exchange 2010 and also Domain controllers all to new hardware. I have set up a test lab and have mirrored it as close as possible to what the production is and will be. I have a test lab set up with the servers being migrated (both 2003 and both DC's with one hosting exchange2003) they have been p2v'd and brought into VM's for testing. Then a physical server has been set up to represent the new server (hardware) that everything will be migrated to including exchange 2010. I know that it is not recommended practise to install exchange on a dc but the companies budget cannot be stretched to more hardware. Eventually one of the current Servers will be reconfigured to be a second Dc for the new infrastructure. I have set up a new domain tree “new.ad” under the root forest “dom_dom”( this had to be done because the original company who did tis install did not set up things right and name the domain dom_dom, Underscore not supported for ex2010 install. I then after great difficulty manage to install exchange 2010 on to the new Dc “dc1.new.ad” i had a lot of Dns issues, replication issues, account access problems, anyhow solved tested and moved on. I have used ADMT to migrate a user from dom_dom AD 2003 native to new.ad AD 2008 and moved mailbox with mailbox move request to the new server Db under new.ad domain, mailbox was shared and all users from old domain and users in new domain can access this mailbox fine. As i am near then end of testing something dawned on me like a brick wall, i have to remove the old dc's from the domain obviously after everyone is migrated and exchange removed public folders re-homed, address lists converted, send connectors set up etc.... Would i be able to remove (dcpromo) both dc's from the infrastructure and keep only the one that now holds Schema master, Domain naming master roles as well as it domain roles PDC, RID and Infrastructure. In other words i want to remove the old dc's from the forest root domain. Can this be done? Just a note that the new hardware will be quite adequate, The physical sever replacing the 2 old very old dc's is a HP dl380 g7 2 quad cpus 8 gb ram with 2 sas 146gb discs raid 1 mirrord for OS, 3x300 Gb sas riad 5 with hot spare and 2 x sas 146 gb for exchange logs files raid 1 mirror. Os windows 2008 r2 64 bit .

Yes, you can do it and there shouldn't be any issue. Just double check that you have moved all the roles to the DC which will be there in production before removing two old DC's. I would recommend that you have more than 1 DC and GC in the environment. Cheers,Gulab | MCTS-MCITP Messaging: 2010 | MCTS-MCITP Messaging: 2007 | MCC 2011 | Skype: Gulab.Mallah

Thats Great thank you. I agree i will be re-building one of the servers ( the current exchange 2003 server) once everything is over to the new domain as a second DC and GC for the new domain. If only the domain had a "." and not an Underscore i would not have to go through all this. oh such is life. Great help though thanks again......