I dont know if redhat8 will run on a 166 or not...
you can download several distro(butions) from
http://www.linuxiso.org
You may want to check out KNOPPIX - I have not tried it, but it is a distro that runs off the cd-rom - linux experience without the formatting, That way, you can learm about linux without trashing the windoze machines...
You may also want to check out
Cygwin it is a unix like environment for windows...GNome and KDE desktops are both available with it...
You can run some windows programs under linux with a package called WINE - runs on most distros..
Linux has drivers lots of things, your current drivers probably wont work..
google is your friend... google search for the codecs and linux you are interested in for more info on them...
Good luck and let us know if you have anymore problems/questions...