I am trying to upgrade my anti-virus software on an NT
4.0 SP4 from NAV 2000 to the current NAV 2003 using a
Systemworks 2003 installation CD. the message:

"Installation Package cannot be installed by the Windows
Installer service. You must install a Windows service
pack that contains a newer version of the Windows
Installer service."

What does this mean? Will an SP6 upgrade fix this
proglem? Or do I have to upgrade to a newer server
operating system like the Windows Server 2000? Am I using
the wrong installation CD?

Thanks in advance!