If your modem is an HCF modem it should work correctly with the Best Data driver, if it does not you have 2 choices. One choice is to go to the modem manufacturer (recommended) for their latest modem drivers. If you have an HSF modem, then please use these drivers.

Note: The generic software offered here should be considered a stop-gap measure only. In all cases, Conexant urges you to contact the manufacturer for drivers or any technical support issues.
Alternative drivers to Conexant HSF Modem (Windows XP):