Easy. Using VirtualBox (PUEL not OSE, the one with USB support) with TinyXP installed. The whole install could be contained in a 2 GB .vdi file. It's how I deal with iTunes for my iPod touch. My EXT4 media partition is mounted as drive D:\ using VirtualBox's shared folders feature.
If you have a moral issue with the license of using TinyXP, you could also use nLite on a full version to trim down the "fat". You can then allocate 256 MB RAM to the virtual machine and it will run fine.
Since Microsoft is no longer selling/distributing Windows XP (like they did with 98 SE, Me, 2k), I guess it's ok to
obtain it from
less-than-reputable places. There's also the Student Edition of Windows XP, which is supposedly free - if you're a student. And there's also ReacOS (
http://www.reactos.org), a work in progress which will also run fine in VirtualBox, though the software being ran on it may or may not.