Because of the many enhancements and differences between RRAS and Routing and Remote Access, it is recommended that instead of upgrading your server, you reuse the settings from RRAS to configure Routing and Remote Access on a new server running a product in the Windows Server 2003 family. Moving from Windows NT Server 4.0 to the Windows Server 2003 family also provides an opportunity to determine whether you want to continue using your existing remote access settings or update your settings to reflect any changes in your organization.
Before attempting to upgrade, check Windows Catalog to verify whether the Windows Server2003 family supports all of the hardware and devices on the computer that you want to upgrade. For example, if WindowsNT Server4.0 recognizes and supports the network adapter but the Windows Server2003 family does not, then pre-configured networking information, including the protocols installed for RRAS, will not be upgraded. For more information, see the Windows Catalog link on the Web Resources page at http://www.microsoft.com/windows/reskits/webresources.
To upgrade from RRAS on WindowsNT Server4.0 to Routing and Remote Access on a product in the Windows Server2003 family, you must have installed Service Pack 5 and the optional download component for RRAS on the computer that you want to upgrade. For more information on the download component, see the Routing and Remote Access Service Download link on the Web Resources page at http://www.microsoft.com/windows/reskits/webresources.