Oh hell, I just noticed it's from that "How To Geek" dude. While this particular program may well be legit, coming from MS, you can get some inaccurate information from that site (HowToGeek).
There was an instructional of how to do an XP install on a computer that's pre-installed with 7. I tried what he said, and got no further than the initial files loading (you know how XP installs, you have it yourself), then I hit a blue screen. This always happens on large drives, even with SP3 on the disc, and even with the disc being partitioned small enough to install XP on.
But what I plan to do is buy a small SATA drive (120GB) that I know XP will install on. I was getting weaned off of XP Pro, then I discovered XP Media Center Edition (a modified XP Pro, and tricky to install). SP3 has been extended to it too, so it will be around for a while. Anyway, if you ever have the Media Center Edition, you won't want the regular XP Pro again. It's so much more colorful, even the Start Menu is that way. And the media options, there's plenty, even a Dancer & Party Mode. It's a great OS for it's time, and not bad today.
My point is, don't believe everything that you read on that site, it doesn't always work as described.
Cat