if it's anything like IIS, it'd be in your administrative tools if you had XP, NT, or 2000 but you're on Win98. I'm at an Apache server right now, so I can't check for sure. Take a look at this, it may help you:
http://www.phpbuilder.com/manual2/install.iis.php
I got rid of the PWS years ago (so I don't remember anything about it) on my 98 box in favor of Apache. I've got it on the Win98 box and 3 XP machines and it installs/configures in minutes. Granted, there's no GUI for virtual directories and the like, but that stuff is pretty easy once you do it once.
Biggus