Yesterday I asked the migration of exchange 5.5 to exchange 2000 on server 2003.Thanks for the answers. Now I have a different scenario i have to implement. I think it should be easy but i need to know how to implement and If some one has the document on it. My this customer has 5 servers. 2 are domain controllers on windows 2K.One exchange5.5 on NT 4.0,another member server with windows 2000 on which exchange 2K will be installed.There is another server which has sql server. Now we have to migrate the exchange 5.5 to exchagne 2K. I thought it would be simple as i was trying previously.Previously I was migrating the uusers and exchange mailbox on the same domain controller. Now They already have he users ON DC. Only i have to migrate the exchange on the member server.What will be process ? WHere i need to install the Active directory connector? Or do i really need the ADC? Do I need ADMT now ? BEcause users are already part of Active directory.? Please reply me at the earleist. ihave to do it by tommorow. Thanks for the help.