I would think that if you installed an audio card that supported MIDI - that cards' drivers would perform all the MIDI stuff vs having to share/slave/route thru Microsofts MIDI Mapper. However I don't know that for a fact. I've never tried Tiny XP.
your sound card's driver cd should install all your midi shit for you - check for a driver / software update on the manufacturers site. if you dont know what card you have let me know and ill help you out