Symbolic links go bad in msports and pnpports after remap.

NTDEV
1

Hi,

I have a problem with MS-DOS naming of COM ports (using XP).
If you first boot, login as admin and then open up WinObj you’ll see
symbolic links for your COM# ports in GLOBAL??. If you then proceed to
change the COM name that one of the ports uses, via the advanced properties
in devmgr, the new symbolic link created as a local MS_DOS name and will be
located somewhere under Sessions\ in WinObj.

If I understand things correctly this is happening because of the call to
DefineDosDevice that pnpports (and I assume msports) makes.

This is fine until you log off and back on as a different user. As soon as
you do that the COM port is effectively lost.

The question is, how would you fix it so that the new COM name would be
available to all users…apart from rebooting?
My guess is that the call to DefineDosDevice should have the COM# name
appended onto GLOBAL\ (for example GLOBAL\COM3) however I am not sure this
woudl be the correct way to go.

To me this looks like it could be a bug that should be fixed in XP (others
as well??).

Thanks, Chris

2

Well…DefineDosDevice fails with GLOBAL\COM# and Global\COM#…it was worth
a quick try :slight_smile:

Chris

“Chris Dore” wrote in message
news:xxxxx@ntdev…
>
> Hi,
>
> I have a problem with MS-DOS naming of COM ports (using XP).
> If you first boot, login as admin and then open up WinObj you’ll see
> symbolic links for your COM# ports in GLOBAL??. If you then proceed to
> change the COM name that one of the ports uses, via the advanced
properties
> in devmgr, the new symbolic link created as a local MS_DOS name and will
be
> located somewhere under Sessions\ in WinObj.
>
> If I understand things correctly this is happening because of the call to
> DefineDosDevice that pnpports (and I assume msports) makes.
>
> This is fine until you log off and back on as a different user. As soon
as
> you do that the COM port is effectively lost.
>
> The question is, how would you fix it so that the new COM name would be
> available to all users…apart from rebooting?
> My guess is that the call to DefineDosDevice should have the COM# name
> appended onto GLOBAL\ (for example GLOBAL\COM3) however I am not sure this
> woudl be the correct way to go.
>
> To me this looks like it could be a bug that should be fixed in XP (others
> as well??).
>
> Thanks, Chris
>
>
>
>