Cannot Delete Unwanted COM ports - Windows 7

Question

I recently installed a Cannon wireless printer for temporary use, the drivers of which set nearly all my COM ports to be constantly in-use (an occasionnal bug noted in the ReadMe after installation with no fixes - thanks Canon idiots!).

I have now deleted the printer and drivers but the ports (COM 1-2,4-13 & 15-32) constantly show up as (in-use). Note that they don't appear like this directly in device manager, but do if I try to re-assign a COM port on some hardware (Device Manager -> Port Settings -> Advanced).

I have tried deleting the ports in Control panel -> Print Server Properties but I get the error message 'Selected ports cannot be deleted. The request is not supported'.

I have also tried to delete the ports through Print Management, but here I get the error 'The selected port cannot be deleted. This operation is not supported.'. If I try to configure the ports I get the error 'The selected port cannot be configured. Operated could not be completed (error 0x00000057).

Does anyone have any alternative methods of getting rid of the in-use status from these ports? I work often with embedded hardware connected over USB so need my COM ports free.

Answer 1

Try this:

First stop the "Print Spooler" service.
Then go into Regedit and find the key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Print\Monitors
If there is a sub-key with Canon in the name delete it. That should get rid of the Canon printer-ports altogether.
There could also be Canon stuff under HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Print\Providers. If so, get rid of that as well.

Don't forget to restart the Print Spooler service.

Answer 2

(Old question, but hey.)

Here is how I delete phantom (disconnected) COM ports:

1. Open a command prompt
2. set devmgr_show_nonpresent_devices=1
3. start devmgmt.msc to open Device Manager
4. Click Show hidden devices on the View menu of Device Manager
5. Delete the phantom ports one by one

I use this procedure commonly. I've designed USB VCP hardware and over time end up with umpteen new VCPs on my machine (from plugging in and checking other people's dongles).

Answer 3

Have you tried using an Admin command prompt?

net use com1 /delete

Answer 4

This is a long shot, but I had success with this before on another brand of printer (HP) with hopeless drivers...

Go into device manager
In the menu enable "Show hidden devices"
Then look for Canon devices and disable them.
(Often such fake ghost com-ports are generated by a fake device-driver.)
This just might free those com-ports. (Reboot might be required.)

Answer 5

I am assuming that you don't need the Canon drivers any more as you said it was for temporary use. If so, I believe that System Restore will help you.

On Win7, Go to Control Panel - System and Security - System, open "system protection", click "System Restore" button, select "Choose a different restore point" and check "Show more restore points". If you can find a restore point made before installing the drivers, the system will be recovered successfully and your hardware configuration will be just like you didn't install the drivers.

This activity doesn't affect on your personal files as per this FAQ.

Answer 6

What I ultimately did to clear the offending ports was to assign the port number of COM1 (the one real physical COM port) to each of the offending port numbers, accept the warning that it was in use, and then, after having assigned it each of the in-use numbers, returned it to COM1. After that, all COM ports were available.