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Nikobus - What should I do when the message "Opening the COM port has failed" appears on the computer screen when connecting a computer to a Nikobus installation?

Depending on your version of Windows, you can manually change the COM port settings (assigned to the USB/serial adaptor) by following the steps listed below.

Windows XP

  • Open the configuration screen.
  • Select “System”.
  • Select “Hardware”.
  • Select “Device manager”. You then see a list of all parts of the PC. Under “COM & LPT ports”, you will find the USB/serial adapter (Prolific), together with the COM port assigned to the adaptor. If this COM port is not COM1, 2, 3 or 4, then you can adjust this manually.
  • Select the USB/serial adapter and right click.
  • Select “Properties…”.
  • Select “Port settings”.
  • Select “Advanced”.
  • In this menu, change the COM port to COM1, 2, 3 or 4.

Windows Vista

  • Open the configuration screen.
  • Select “Hardware”.
  • Select “Device manager”. You then see a list of all parts of the PC. Under “COM & LPT ports”, you will find the USB/serial adapter (Prolific), together with the COM port assigned to the adaptor. If this COM port is not COM1, 2, 3 or 4, then you can adjust this manually.
  • Select the USB/serial adapter and right click.
  • Select “Properties…”.
  • Select “Port settings”.
  • Select “Advanced”.
  • In this menu, change the COM port to COM1, 2, 3 or 4.

Windows 7

  • Open the configuration screen.
  • Select “System”.
  • Select “Hardware”.
  • Select “Device manager”. You then see a list of all parts of the PC. Under “COM & LPT ports”, you will find the USB/serial adapter (Prolific), together with the COM port assigned to the adaptor. If this COM port is not COM1, 2, 3 or 4, then you can adjust this manually.
  • Select the USB/serial adapter and right click.
  • Select “Properties…”.
  • Select “Port settings”.
  • Select “Advanced”.
  • In this menu, change the COM port to COM1, 2, 3 or 4.