Migrating from a Windows NT domain to Windows 2000 Active Directory domain should be relatively painless. But all too often, the process is hampered and hindered by little things that make a big mess.
Having a clear understanding of the differences between how NT maintains domains and how Windows 2000 Active Directory maintains domains can help avoid most problems.
Here are a few common sand traps that many IT professionals overlook when performing their first migration:
Pre-loaded PDC definitions in LMHOSTS and HOSTS files are the first problem. If a server or client loads an LMHOSTS or HOSTS file with a pre-defined Windows NT domain controller, it will not be able to see or recognize the new Windows 2000 domain controller. You must either delete these files or edit them to remove the DC definitions.
Even though Windows 2000 can rely exclusively on AD to maintain the shared resource list, it still participates in the Master Browser service as long as it is in mixed mode. In mixed mode, a Windows 2000 server (especially a domain controller) will always win browser elections over any Windows NT system. If you elect to disable the Windows 2000 system's participation in the browser service, you will effectively remove the ability for non-Windows 2000 AD clients to find resources on the network. To eliminate this problem, you must configure one of the Windows NT systems to be the domain master by setting IsDomainMaster to True in the HKEY_LOCAL_MACHINE
Windows NT user profiles are not compatible with Windows 2000 user profiles. A Windows 2000 server can act as a repository for any type of profile, even Windows NT. But a Windows 2000 system will not load a Windows NT user profile and vice versa. Maintaining both Windows NT and Windows 2000 systems on your network with roaming profiles will require that you have different accounts for logging onto Windows NT and Windows 2000 systems.
James Michael Stewart is a researcher and writer for Lanwrights, Inc.
This was first published in March 2002