do I need MS Plus ?

Hello

My system:

PC Clone
Celeron 400
128 Mgs Ram
13 Gig HD
Win 2000 Pro
Norton Systemworks 2001 installed.

I just downloaded and installed two cool screensavers that I have seen around : MS Dangerous Creatures, and MS Underwater.
But they won't run. Their config panel tells me that I need to have System Agent set up on my computer.
Unfortunately, Windows Help doesn't have anything to say about System Agent.
I went to the Microsoft site and downloaded and installed something called MS Agent. No difference, no help - the screensavers still won't run.

Anyone have any idea how I can get these great screensavers to run. I hope I don't have to buy Plus, cause I don't want to.

Thanks,

Jim Martindale