Hot Topic: guest access to a public PC?

I am setting up a computer to run at the back of my church. it is intended that people will be able to access the interent through to access resources online. It is running windows 98 (2nd ed), and has a floppy drive, cd drive and not a lot else. I am looking for a way to limit the users abilities when using the system. I would like them to not be able to install any programs without a password, or similar. also password blocking access to the cd drive/floppy drive would be handy. does anyone know of a method to do this, or any software that will do it for me?
http://www.techsoup.org/forums/index.cfm?fuseaction=read&forum=2009&id=56001&cid=117