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Port Already Open

Problem: Error 602: Port in use. Port already open. Your modem is being used by another application.

Operating Systems: Windows XP, 2000, ME, 98 & NT; Macintosh OS X, OS 8-9

If the port is already open, another application has control over the modem.

This can sometimes occur with errant applications (poorly written software) not closing the port, or terminating abnormally. If this is the case, it may be necessary to power cycle the computer before the modem will be recognized.

If some other device is actually using the modem (such as a voice/fax program or you are already on a dial-up connection), the solution is to terminate the other task, or to disable auto-answer features in its software.

Windows users can get a list of applications that are running (and might have the port opened) by pressing CTRL+ALT+DEL and selecting the TASK LIST or TASK MANAGER (NT). This will display the actual program names - it may be difficult to pinpoint which, if any, programs are accessing the modem. Terminating tasks are about the only way - however, if you terminate certain tasks, your system may crash or become unstable. With Windows 98 ending the rnaapp task may solve the problem.

If a program is being run automatically (check your start-up group) that accesses the modem and leaves the port open - you need to either change the configuration of that program, or remove it from the STARTUP group. In rare cases, you may need to completely uninstall the application that is causing the problems.

To check for items in the Startup folder, go to Start > Programs > Startup (Note: If MSN Quickview is in the folder, it is recommended you remove it). You should also look at active icons in the System Tray for suspicious programs that might be using stealing the port from the modem. To disable items, go to the Start-up tab of the System Configuration Utility. Some common programs that cause problems are BackWeb and other 3rd party communications software.

How to Power Cycle your Computer and Modem

Occasionally you computer will encounter errors that leave the modem status in an 'unresolved' state. This causes problems when you try to connect again. If this occurs, you will need to shut down and restart your computer in the following manner:

1. Close all running programs.
2. Windows: Click on the Start button on your task bar and choose Shut Down. If necessary, select the option to Shut down or Turn off the computer. Macintosh: Click the Special menu and choose Shut Down.

   Do not select the Restart option.

3. If the computer displays the message It is now Safe to Shut off the Computer, turn the power off.
4. If you have an external modem, make sure to turn the power off on it as well. If there is no on/off switch on the modem, you may have to unplug the modem's power supply.
5. Wait approximately 2 minutes, then turn your computer and modem (if external) back on.

Also related to this problem: Difficulty disconnecting