I need a plugin for Windows Media Player 9 that can create MP3 creation from disks. It needs to be for windows 98 SE or lower format. I looked at Microsoft.com, but they only had them for XP.

try this:
http://www.updatexp.com/codec-for-windows-media-player-9.html

edit
or this:
http://forums.winforums.org/showthread.php?t=3078

Are you talking about an mp3 ripper? There are plenty of third party programs out there.