Guide to Identifying COM Port Numbers in Windows for Device Configuration

How to Find COM # for Port



Troubleshooting: How to find COM # to Assign to a Machine

- Right Click on Computer or My Computer and click Properties


- Click on Device Manager in upper left column

(if XP or earlier, click on Hardware, then find Device Manager button)


- Click VIEW on main menu.  Change to DEVICES BY CONNECTION


- Find your device (may say something like Serial Hub or Comtrol Serial device Server)


- Click the little arrow next to device to expand that device and it will show you all of your ports (see example below).


- Look for port with lowest COM# and that should be the first physical port on your device.  The ports may not appear in order because of the way Device Manager organizes numbers.

- As you can see from the example below, Port 10 is before Port 2 because COM 10 starts with a 1.  To find the COM port of a particular physical port, look for the number of the physical port and the associated COM # will be in parentheses.

 - Keep in mind that some devices, like Comtrol Devices, start with port 0, so the 16th physical port, will actually be numbered Port 15.



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