Re: Too little, too late.
Try using a 13 year old install of XP on a 13 year old PC and you'll find that it doesn't work...very well at all.
Don't know about 13-year old, but 7-year-old is fine. Just as long as it has enough RAM for modern XP (1Gb minimum, 1.5Gb better).
Insert XP with SP3 DVD, install
Crank up Windows Update, install updates, reboot, install more updates, iterate several times until up to date. Tedious, slow, bandwidth-consuming, but it works. If you have a volume license for Office you might also install that, upgrade to Microsoft Update, go around the updating loop a few more times. And install MS Security Essentials if you don't have any other AV to install.
Once you have an up-to-date virgin XP install the smart thing to do is to sysprep it. Then boot a stand-alone Linux disk such as SystemRescueCD, re-size the boot partition as small as reasonably possible, and generate an image of the used part of the disk. (Alternatively you could use one of the paid-for snake-oil imaging tools for folks who don't understand the previous sentence).
Make sure you can restore and boot your image onto another PC with a blank disk.
And now you'll be able to install up-to-final-date XP onto 7-year-old or maybe 13-year-old PCs in half an hour, for the forseeable future ....
Until Microsoft shuts down their XP activation servers ....