Carsten,
Thanks for your reply. Reading the thread you pointed me at will make me pause before continuing, but I'd like to try to figure out what to do when the problems in that thread have been resolved, and I can continue....
...I had tried to get the SEP client to install on the SBS2003 server. It wouldn't install, hence my first question, because I thought I might be trying to do something that I shouldn't.
The installation gets part way through, and then rolls back and aborts. There's no final error message or explanation given. I tried doing this install from the CD package I downloaded, from the 'find unmanaged computers' in SEPM, from the deployment wizard, and got the same result in all cases.
I previously had Client Security 3.1 installed, but installed it prior to starting to install SEP. Is it possible there's something left hanging around that is preventing the install of SEP on the SBS2003 machine? Or should I be looking for something else?