It will not work as a boot disc because it is a copy. You need Action Replay / Gameshark or DVD Region X to boot.
The purpose of the downloadable boot discs is for a triple swap needed to boot DVD-R copies. Using an old copy of Action Replay as the first boot disc.
It would be much simpler to shell out £20 and get one of these CD's I advise AR2 as it will allow DVD-R booting.
Boot guides can be found
www.psxcopyworld.co.uk