Is there one for Vista or 7? I had a quick look to see if it was any easier, but it looked to be third party tools again.
WinToFlash, that's the one I ended up using. It worked alright but I haven't got a clue why after the installation Windows complained half its files were unrecognised versions. I created an ISO from a slipstreamed XP/SP3 disc I made a few years back and have never had any problems with until today.