JSI Tip 7500. What operations are performed by the Microsoft Windows Server 2003 Adprep.exe utility that is used to prepare a Microsoft Windows 2000 forest or a Windows 2000 domain for the installation of Windows Server 2003 domain controllers?

Microsoft Knowledge Base Article 309628 contains the following summary:

This article discusses the operations that are performed by the Microsoft Windows Server 2003 Adprep.exe utility that is used to prepare a Microsoft Windows 2000 forest or a Windows 2000 domain for the installation of Windows Server 2003 domain controllers.