When upgrading your domain from Windows NT Server 4.0 to Windows 2000 Server or Windows Server 2003 Active Directory, there are two essential elements. Without properly addressing these elements, your upgrade or migration procedure will fail. These two elements are DNS and NTFS.
Active Directory relies upon DNS. There is no way to deploy Active Directory without a local DNS system. However, not just any DNS solution will suffice. The DNS solution must support SRV RRs since these are used by Active Directory to locate domain controllers. The DNS solution included with Windows NT Server 4.0 does not support SRV RRs and thus cannot be used to support Active Directory.
Another related feature that is not strictly required but highly recommended is Dynamic DNS (DDNS). DDNS is supported and native to Windows 2000 Server and Windows Server 2003. This is basically an enhanced form of DNS that allows domain systems to update their DNS records automatically.
If your current DNS server is also a Windows NT Server 4.0 domain controller you can perform an upgrade, install to Windows 2000 Server or Windows Server 2003. However, this process will not result in the correct resource records in the zone, plus it will not be a DDNS solution. A better way to perform the upgrade activity is to first deploy a Windows 2000 Server or Windows Server 2003 based DNS system. Then perform a zone transfer from your previous DNS to the new DNS. Next, make the new DNS authoritative for the zone and configure it to support dynamic updates. Finally, configure the previous DNS system as a client to the new DNS system, then perform the upgrade.
Active Directory domain controllers also require NTFS v.5 on the boot partition. NTFS is required for the storage of the Active Directory database. If your boot partition is already formatted with NTFS v.4 under Windows NT Server 4.0, then when you upgrade the domain controller to Windows 2000 Server or Windows Server 2003, NTFS will automatically be upgraded to v.5. If you are not using NTFS, you'll need to convert the boot partition to NTFS before the upgrade is started.
James Michael Stewart is a partner and researcher for ITinfopros, a technology-focused writing and training organization.