If the resources that the modem is configured to use do not match the resource settings for the serial port, physically configure the modem to use different resources or modify the resource settings for the serial port in Device Manager. For information about how to configure the modem, consult the documentation included with the modem, or contact the modem's manufacturer. Quit any running communication programs. Close all communication programs. To close a program, click the program, and then click End Task .
Repeat steps one and two until all unnecessary programs have been closed.
Disable the modem in Device Manager, and then re-enable the modem. On the System Properties dialog box, click the Device Manager tab. Under the Device Manager tab, double-click Modem . Click the appropriate modem, and then click Properties . On the General tab, click Disable in this hardware profile .