Paul, you're definitely my kinda guy (I thought I was the only one who said things like "Yee Haw!" in similar situations
Yes, it is often easier to just reinstall XP (or 2000, which is what I have) clean at this point (especially if you've FUBAR-ed something, but often even if not "really" FUBAR-ed), and yes, it is a PITA, and I would suggest not stressing too much about it-- get the basic install done, get it updated (17 billion reboots), install your AV software, and just stop there and get back to Linux.
You may find that you won't actually be using XP all that much once you have Linux properly installed, and you'd be unhappy having spent all that time to reinstall and reconfigure an OS that you're not even using most of the time. Since reformatting and repartitioning my drives and reinstalling 2000 and installing Gentoo 2 months ago, I have spent about 30 minutes tops in Windows, and most of that was to check or cross-check settings. It would have been even less had I not done a Windows Update or two to cover publicized exploits and to update my AV software. So, very unlike me, Windows is using the Standard Windows desktop, pretty much nothing is installed (including my standard tweaks), and Windows is "just there", like it says in my profile. I'd wipe it completely, except some games that I'd like to test under Wine have to be installed under Windows (the games supposedly work, but the installers don't), so I'm keeping it around for that reason.
But I really don't use it, and you might not either, so don't invest yourself in it assuming that you will-- at least not right off the bat. It's not going anywhere, after all