Reusing COM numbers

  • Thread starter Thread starter lesaint
  • Start date Start date
L

lesaint

I'm trying to add a multi-port COM card to a system. Everything works, except
the COM names I get start w/ COM5.

Is there a way to "clear" the old COM2-COM4 assignments so that they could
be available when I add my new ports?

Thanks for your help.
 
"lesaint" <lesaint@discussions.microsoft.com> wrote in message
news:F5FB353D-090D-4CF9-9E6F-4BA10BE4CEB7@microsoft.com...
> I'm trying to add a multi-port COM card to a system. Everything works,
> except
> the COM names I get start w/ COM5.
>
> Is there a way to "clear" the old COM2-COM4 assignments so that they could
> be available when I add my new ports?
>

Yes.

You need to do the following.

Open up a command window.

Type "set devmgr_show_nonpresent_devices=1" (without the quotes obviously).

then type "start devmgmt.msc"

The device manager should now open. The 'View' menu at the top has an
option to 'show hidden devices'. Select this option (a tick will appear
next to it). Device manager will now show every device which is connected
and every device which has ever been connected (as a fainter icon). If you
now go to the bit that shows the COM ports, you can highlight and uninstall
those COM ports that you no longer require.

Once done click 'OK' and then close the command window.
 
and once you've done all that, you will likely need to reassign the new
COM ports (e.g. COM5) to the COM# you want.
___
"M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message
news:4768fce4$1_1@glkas0286.greenlnk.net...
>
> "lesaint" <lesaint@discussions.microsoft.com> wrote in message
> news:F5FB353D-090D-4CF9-9E6F-4BA10BE4CEB7@microsoft.com...
> > I'm trying to add a multi-port COM card to a system. Everything
works,
> > except
> > the COM names I get start w/ COM5.
> >
> > Is there a way to "clear" the old COM2-COM4 assignments so that they
could
> > be available when I add my new ports?
> >
>
> Yes.
>
> You need to do the following.
>
> Open up a command window.
>
> Type "set devmgr_show_nonpresent_devices=1" (without the quotes
obviously).
>
> then type "start devmgmt.msc"
>
> The device manager should now open. The 'View' menu at the top has an
> option to 'show hidden devices'. Select this option (a tick will
appear
> next to it). Device manager will now show every device which is
connected
> and every device which has ever been connected (as a fainter icon).
If you
> now go to the bit that shows the COM ports, you can highlight and
uninstall
> those COM ports that you no longer require.
>
> Once done click 'OK' and then close the command window.
>
>
 
[Top posting corrected]

"none" <nospam@bogusaddress.com> wrote in message
news:Os7Gm%23jQIHA.4196@TK2MSFTNGP04.phx.gbl...
> "M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message
> news:4768fce4$1_1@glkas0286.greenlnk.net...
>>
>> "lesaint" <lesaint@discussions.microsoft.com> wrote in message
>> news:F5FB353D-090D-4CF9-9E6F-4BA10BE4CEB7@microsoft.com...
>> > I'm trying to add a multi-port COM card to a system. Everything
> works,
>> > except
>> > the COM names I get start w/ COM5.
>> >
>> > Is there a way to "clear" the old COM2-COM4 assignments so that they
> could
>> > be available when I add my new ports?
>> >
>>
>> Yes.
>>
>> You need to do the following.
>>
>> Open up a command window.
>>
>> Type "set devmgr_show_nonpresent_devices=1" (without the quotes
> obviously).
>>
>> then type "start devmgmt.msc"
>>
>> The device manager should now open. The 'View' menu at the top has an
>> option to 'show hidden devices'. Select this option (a tick will
> appear
>> next to it). Device manager will now show every device which is
> connected
>> and every device which has ever been connected (as a fainter icon).
> If you
>> now go to the bit that shows the COM ports, you can highlight and
> uninstall
>> those COM ports that you no longer require.
>>
>> Once done click 'OK' and then close the command window.
>>
>>

> and once you've done all that, you will likely need to reassign the new
> COM ports (e.g. COM5) to the COM# you want.
>

Please don't top post, it upsets the logical flow of the discussion.

Windows XP allocates the COM ports in order, so the first device connected
gets the next available COM port number, but disconnected devices still
count. In the OP's case, it would seem that he already has a COM1 device,
so the next device he installs that needs a COM port will take COM2. Some
(but not all) drivers for devices allow you to change the port number.
 
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