How do I find the device which has Com Port X reserved - want to reclaim the port num for different device

Solution 1:

"Method Using Elevated Command Prompt"

From Start Menu type cmd into search bar right click on cmd.exe and select run as administrator

at UAC select yes to allow Windows Command Processor Program to make changes.

At the Command prompt type

SET DEVMGR_SHOW_NONPRESENT_DEVICES=1 (Followed by enter)

Then to open device manager type

DEVMGMT.MSC (Followed by enter)

In device Manager select View / Show hidden devices

Expand Ports (COM & LPT)

Hidden ports reserved will be shown with greyed out symbol & associated manufacturer / device type

screen shot device manager ports

To re-hide non present devices in future - from an elevated Command prompt type

SET DEVMGR_SHOW_NONPRESENT_DEVICES=0 (Followed by enter)