Every place but the obvious? The Motorola website?
EDIT: By the way, when some dip tells you Vista doesn't run well, their full of crap. Out of all my PCs (and I have a bunch), my Vista has run flawlessly for the last 4 years, STILL as fast as the day I installed it. Usually when someone makes a statement like that, they haven't a clue themselves on how to properly run and maintain a PC.
EDIT: I did a search and found that the motorola sm56 is a fax modem for a phone line, NOT a sound card.