Modems built prior to July 1999 did not have firmware that will operate in Win2000, so unless your modem firmware has been upgraded since July '99, you will need to perform this upgrade or have it done. You can check the firmware version of the modem by using one of the following 3 methods: -Use Hyperterminal to send an ATI command to the modem and check the modem's response. -Select "more info" on the diagnostics tab of the Modems Control Panel. -Contact Multi-Tech tech support and give them the modem's serial number. If your modem contains 4.xx firmware, then it must be upgraded. If your modem contains 5.xx or higher firmware, then it is ready for Win2000, and you only need to install the driver for Win2000. If your modem currently has 4.xx firmware, you will need to upgrade the modem firmware first, before you can install it on a Win2000 machine. You can perform this firmware upgrade yourself, or you can send the modem to Multi-Tech's repair department for a firmware upgrade. Firmware update page: http://www.multitech.com/SUPPORT/MultiModemUSB/firmware.asp MultiTech Support: U.S. and Canada 800-972-2439 M-F, 8:30am - 5pm CST International +763-717-5863 M-F, 7am - 3:30pm CST -or- support@multitech.com