Seriously, a really good option here could be to install Linux native on the box, and then VMware Server (free), or VMware Workstation (payware), on top of that. And then install XP inside VMware, and run it that way.

Then you can easily automate anything about the box that you want, including on-the-fly backups (or at shutdown, or..), with the added bonus of having VMware snapshots (one for Server, or an entire tree of snapshots for Workstation) to do instant system saves/restores at will.

Cheers