In the meantime, I confirmed you cannot use the tool to build a Windows XP install DVD. By experiment, I was able to demonstrate to myself that this tool works only with Vista and Windows 7 ISO files. I also discovered an informative blog at Rafael Rivera’s fascinating Website “Rafael’s Within Windows” (worth some exploration over the holidays for those interested in Windows internals and some extra time on their hands). FWIW, Rafael also explains why the tool doesn’t work with some ISO images (including the aforementioned XP ISO) — namely, it checks for certain image elements called Anchor Volume Descriptor Pointers (aka AVDPs) at both the head and tail of the ISO file. The tool checks for an AVDP in both places, and when it doesn’t find both where it expects them to be, it emits the following error screen:

If the tail-end AVDP is missing even from an MS-supplied ISO, this is what you see

The reason why I already love Rafael, is that he not only points out the problem which may be simply described as a failure to put the tail-end AVDP in the right location in those ISO files the tool won’t handle, he also provides a tool to patch the ISO image so it will work with the Windows 7 USB DVD Download Tool. And, he’s submitted a patch to the CodePlex project for the tool so that this oversight will be fixed in the next upcoming release (whenever that may be: I can’t find any info on this).

So, if you’re going to use this tool, and want to extend its functionality to other ISOs besides Win7 and Vista, grab Rafael’s tool to fix those ISO images so the tool will work properly with those files. Enjoy!