Overview of Upgrading Active Directory Domains
Applies To: Windows Server 2008, Windows Server 2008 R2
By upgrading your network operating system, you can maintain your current network and domain configuration while improving the security, scalability, and manageability of your network infrastructure.
Before you upgrade your Windows 2000 or Windows Server 2003 Active Directory domains, review your business objectives and decide how they relate to your existing Active Directory infrastructure. Although your objectives might not require other significant changes to your existing environment, the operating system upgrade is an opportune time to review your existing Active Directory design, including your Active Directory logical structure, site topology, and domain controller capacity. You might find opportunities for increased efficiencies and cost savings that you can incorporate into your upgrade process. In addition, ensure that you test your upgrade process in a lab and pilot program.
When the domain upgrade process is complete, all domain controllers will be running Windows Server 2008 or Windows Server 2008 R2, and the Active Directory Domain Services (AD DS) domains and forest will be operating at the Windows Server 2008 or Windows Server 2008 R2 functional level. At the Windows Server 2008 R2 forest functional level, you can take advantage of all the advanced AD DS features. For more information about advanced AD DS features for AD DS functional levels, see Enabling Advanced Features for AD DS.