We have a windows 2000 domain with 2 DC's. We had a windows 2000 server with exchange 5.5 running. That server died. When it did, the old IT guy installed a 3rd party mail server, reconfigured all the outlook clients to use POP3, and then pointed them at the new mail server. Now, 1 year later, we happen upon the client, and they want to go back to exchange. They have a copy of Exchange 2000 Ent edition, paid for, that they want to use. When we try to install however, it is asking for the Exchange 5.5 server, which is no longer a memory, much less a working server. Question; how do we remove any trace of the Exchange 5.5 server from the domain, so that we can then install Exchange 2000 server.