Comment 2.1 Gb HDD (Score 1) 410
I got bored one time and installed XP Pro on an old 2.1 Gb drive I had lying around.
It actually worked absolutely fine, without a problem of any kind. Of course, when I plugged in the ethernet cable it found the automatic updates, and gave me 'low disk space' warnings and shut itself down while trying to download them.
Good times.