Peter,

Your suggestion did the trick.  Following these instructions prior to
running the standard 'setup' program resulted in a successful installation
on our Notes 4.5/Windows NT servers:

1. Stop the "Netfinity Support Program" NT service.
2. Stop the "Lotus Domino Server" NT service
3. Search for and rename all versions of UNINST.EXE residing on any of the
   server hard drives.  It will usually be found in C:\WINNT.  ADSM
   installation will install its own version of UNINST.EXE.

My Notes person suggested stopping Netfinity prior to stopping Notes
because he's had problems stopping Notes without stopping Netfinity first.
This seems to be related to Netfinity V5.

ADSM installs its own version of UNINST.EXE in C:\WINNT but won't do so if
one is already there.  I don't know whether the prior version came with NT
itself or some other package (Netfinity?).  For now, I've renamed the old
version but left the new version in place after ADSM installation.

Thanks,
Dennis

BTW, someone else in the forum (florin.popescu AT bas-europe DOT com) had
suggested verifying the presence of a C:\TEMP directory and a TEMP variable
pointing to it.  Thanks to them for the suggestion but I already had both
of those in place.