Certificate Server 1.0 cannot be upgraded directly from Microsoft Windows NT 4.0 to Windows Server 2003. If you continue, your Certificate Server settings will not be saved, and Certificate Server will be automatically uninstalled. If you upgrade first to Windows 2000 and then upgrade to Windows Server 2003, all your Certificate Server settings will be preserved.
For more information about Windows Server 2003 Certificate Services, see the Microsoft Web site.