Connecting a computer to multiple version 3 NetBotz devices adds a com port for each device.
NetBotz version 3 appliances.
When connecting to a version 3 NetBotz device via USB, drivers need to be installed so you can communicate to the device for initial communications or, in some cases, troubleshooting. This driver creates a com port so the USB connection can communicate as a serial port.
Each time you connect to a different NetBotz appliance, another instance of a serial port may be created so if you are configuring multiple units this way, you may create multiple com ports.
If you do not wish to manually remove all of these ports, the driver manufacturer (FTDI) has created a driver removal utility.
This file can be obtained here at http://www.ftdichip.com/Support/Utilities.htm
The sectioned marked ""CDM Uninstaller"" - Driver Removal Utility has the direct link to the downloadable file to remove the drivers and com port entries.