I get an error message saying the port is already open

This message is similar to the "cannot communicate with modem" message.  This message means there is a problem with how the computer talks to the modem, or that your modem has a problem.  It is best to consult the manuals that came with the modem or the manufacturer because troubleshooting this problem requires an experienced user.  If your computer is still under warranty from the manufacturer, it would be a good idea to call them first.  If not, you should call your local computer service center for help.  For those that are savvy enough, here are some suggestions to try on your own:

• Check the COM port your modem is on and ensure that COM port is DISABLED in your computer BIOS
• Remove the modem from the device manager and restart Windows.
• Go into Safe Mode to remove your modem and all COM ports and restart Windows.
• Try to plug your modem into a different slot on your motherboard.
• Download the latest version of your modem drivers.
• Ensure there is no software installed that could conflict with the COM ports, such as Fax, Camera, or Palm Pilot software.

Refer to Microsoft article #Q168222 for more information.