I have the free-after-rebate PCTel Winmodem (I got it from Staples on XP Thursday, but I believe it is free-after-rebate from CompUSA on day-after-thanksgiving). It comes with Win2K drivers and works on XP. Note I mostly use it as a fax, so I cannot vouch for its quality as a dialup modem, but it works. I have indeed heard that others have had problems, but My Mileage Is Excellent.