Can you be sure which exactly? that could be forth gen? if so....
Mod it with ROCKBOX. Afterwards you can just plug it into any computer and drag and drop. You need to backup the music on it first(if required). You can use mediamonkey on windows for that.
There are tons of reasons to mod with Rockbox.
1) better sound quality 2) better battery life(in most cases) 3) much more support with different audio files 4) HDD/Flash drive like response for drag and drop(NO MORE RUBBISH ITUNES FOREVER)
* B U R N * D O W N * T H E * D I S C O *: My Three Favorite Kernels-- Linux - emCORE - Rockbox part 1
^ most my post here is balls, but, read the part about rockbox if you want to know more-- my blog about it is in relation to another way to install it on the later Ipod Classic. so ignore that bit, just read about Rockbox. Its worth it
Rockbox - Free Music Player Firmware
edit: of course you have to convince her that running linux on the ipod is also a good idea!! LOL if you can't then that post of mine wasn't that helpful.
OK: you could just download a copy of vista home basic from a download site. (torrents whatever) and then use the keycode that is on the laptop and just reinstall vista. BUT your suggestion of unbuntu is better