This document provides step-by-step instructions for migrating an organization's Active Directory from Windows Server 2003 to Windows Server 2012. It details how to transfer the Flexible Single Master Operations roles, change the Active Directory and domain controllers, transfer the schema master role, and remove the 2003 server from being a global catalog server. The overall process migrates Active Directory roles and services from the 2003 server to the new 2012 server to complete the Active Directory migration.