Quote:
And.. it just worked for me. Fiddly to do the mods -- needed an ISO image editor, and I couldn't find one for Linux. But I did find a cracked copy of a Windows based tool that did the job for me (inside a throwaway VMware snapshot).

You should be able to do most of it using just mkisofs if you can work out a way of extracting the boot floppy image from the ISO. The normal Windows XP CD doesn't do anything special apart from having the boot image embedded in it. It is only the MSDN versions which do tricks like linking multiple files to the same data which allows it to put all the versions onto a single disc.