I have a Tiny PC and it had a 56k HSP modem. When I upgraded to XP home, I tried everything to get that modem to work but it wouldn't. I downloaded every driver I could find to no avail. Eventually bought a new modem for about a tenner from PC world that was XP compatible and it worked straight away. I put the old modem in an old 98se system and it worked no problem. I guess the old modem was not XP compatible.