Hello Dan,

Instead of using an instance of Windows XP solely to use Chirp.. you might try using a bootable Linux CD.  For example, Andy's HamRadio ISO:

   https://sourceforge.net/projects/kb1oiq-andysham/

Assuming your old computer can boot from a USB port, this ISO has Chirp already installed.  If you have a cutting edge radio, maybe the included version of Chirp might not support it but if you use a USB pendrive that has some extra space (the ISO is only 1.9GB), this distro will allow you to do in-line upgrades and upgrade Chirp, etc. and it all stays on the USB pendrive across reboots.  Just like a real hard drive but it's portable!  Something to consider!

--David
KI6ZHD