Upgrading from SBS v4.5 to SBS 2000

Archived from groups: microsoft.public.win2000.setup_upgrade (More info?)

I have a client that owns SBS v4.5 but was never installed
on the server. Instead they loaded Windows 2000
Professional and are running the network as a peer-to-
peer. They purchased some time ago, SBS 2000 upgrade. Of
course I do not want to have to install SBS v4.5 before I
can install Windows 2000 SBS. Can I do a fresh install
with an upgrade license?

I know other operating systems will try to detect a
previous version during the installation. Can you tell me
if I will run into this problem if I try to use an upgrade
license key for a fresh installation.

Any help would be most appreciated.