[feels stupid] I remembered zip disks but forgot utterly about backing up to an optical drive.
Really, though, if we’re going to be opening the case, just bring a laptop and a universal external drive adapter, rip the HD out of that antique and clone it to your laptop over USB3. Fast, simple, easy, and doesn’t depend on the live CD actually working on an antique.
Without opening the case, I think a parallel port iomega drive (zip and I forget what the other two were called? Jaz and something) is your best bet. Need to have a floppy with drivers for Win 9x, though. Finding 9x drivers would probably be the most time consuming part of any of these backup schemes.
