Finally got it. Thanks.

It turns out that you need to only use the FB_INET version on
MSServer 2003. The other version simply doesn't work. I'm sure
there is a reason but I haven't been using Firebird long enough to
know it. And once you try the FBServer version first, it screws up
everything from that point on.

To fix it, I started yet again with a clean install of MS Server 2003
and then simply ran the InstallClassic.bat file.

What's strange is that the guardian and FB do not show up in the Task
Manager. But they are running. There is the normal entry in the
event log that guardian has started and sure enough, I can connect to
the DB.

Thanks for the pointers.
DaveH