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How to install a Virtual Modem on a lower COM Port

Symptom: 

The user already has non-Diva virtual modems installed on the virtual COM ports that are used by the Diva Client Software, or wants to install the virtual modems on a lower COM port than COM 4 due to a legacy application. 

Fix / Solution: 

Edit the registry key

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\DiPort\Parameters\FirstPort

WARNING: Editing the registry can cause serious problems that may require you to reinstall your operating system. Please make sure you have a backup of the registry before you make any changes - consult the Microsoft documentation for more information. Dialogic do not have any responsibility for system problems resulting from the use of the information below. 

• Uninstall & remove the device that is causing the conflict with the Diva.
• Uninstall all Diva virtual modems
• Start the program REGEDIT.EXE and find: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\DiPort\Parameters
• Change the value of the 'FirstPort' Key from 5 to 8 (for example).
• Close REGEDIT and reboot the machine.
• After the reboot, go through the 'Add New Modem' Wizard and select the desired virtual modem. On the next screen when you have to select a COM port, you will now be able to select any COM port from COM8 to COM12.
• Test each modem using Query Modem on the Modem Diagnostic tab
• Reinstall the other device that was causing the conflict.

Note: To assign the virtual modems to a lower port, change the value of the FirstPort key to 3 for example to install a modem on COM 3.