How can I Change the Serial Port Number of My Device in Windows?

Updated Jun 20, 2018

Reported In


  • Serial Cable


  • NI Device Drivers

Operating System

  • Windows

Issue Details

After I installed my serial card, the ports were assigned certain numbers (like COM1 or COM3.) I want to change the assigned number of these ports in Windows. How can I do this?


You can easily re-assign a serial port to another COM port number in Windows. Start by opening Windows Device Manager. Select Start » Settings » Control Panel »System. In the System window which opens, choose the Hardware tab. Then click the Device Manager button.  

In the Device Manager, expand the Ports (COM & LPT) section. You can then right click the serial port you would like to re-assign and choose Properties from the menu that appears. This will open the Communications Port Properties window. Select the Port Settings tab.

This will open the advanced settings for the port. In the lower left corner of the window, you can choose the new port number from the "COM Port Number" drop down menu.


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