AD upgrade

Currently we have 4 NT Servers and 4 W2K Servers (but not an AD environment) ? Our PDC is a NT Server, which I was going to upgrade to W2K Server and also add in the AD option when it prompted me to (if it didn?t do it automatically). I was under the impression that when the upgrade was complete, the domains would have automatically been moved over to the AD environment and could be modified in the AD console. ? Is this correct?