Determining Whether to Upgrade Existing or Deploy New Domains

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Each domain in your design will either be a new domain or an existing domain that has been upgraded in place. Users from existing domains that you do not upgrade in place must be migrated into new domains.

Moving accounts between domains can impact end users. Before deciding whether to migrate users into a new domain or upgrade existing domains in place, evaluate the long-term administrative benefits of a new Active Directory domain against the cost of migrating users into the domain.

If you are upgrading from Windows NT 4.0 to Windows Server 2003, evaluate each Master User Domain (MUD) in your organization to determine whether they are candidates for upgrade to an Active Directory domain. If you are migrating from an operating system other than Windows NT 4.0, plan to create new Active Directory domains. If no Windows NT 4.0 MUD upgrade candidates exist in your current environment, plan to create new Active Directory domains and migrate your existing accounts and resources into them.

For more information about consolidating and upgrading Windows NT 4.0 domains, see "Restructuring Windows NT 4.0 Domains to an Active Directory Forest" in this book.