"HLMencken" <HLMencken@discussions.microsoft.com> wrote in message
news:7BDB5B5F-C2DA-40EC-A13B-7A9D3F710767@microsoft.com...
> I did a bonehead thing when I was troubleshooting a problem recently, w/my
> new Canon SD550 camera connecting to the Canon software in Windows. When I
> first connected the camera, I got the usual dialog box of all the various
> programs on my machine that could connect to the camera and download
pictures
> (Adobe Photoshop Elements, ACDSee, the Canon CameraWindow, etc.).
>
> The bonehead part comes in when I checked the "Always perform this action"
> w/the "Canon CameraWindow" selected. Now when I connect the camera, the
Canon
> CameraWindow always starts, never giving me a choice of which program I
> actually want to use. D'oh! Yes, I know it's doing exactly what it's
supposed
> to do. Problem is, I want the dialog box of choices back, and I don't know
> how to get it.
>
> W/a simple file association, I know you can go into My
Computer>Tools>Folder
> Options>File Types tab, and scroll down until you find the file type you
want
> to change the association to. Trouble is, the camera is of course a
hardware
> device, and I have no idea where to look for the magic place to undo what
I
> did. It is *not* in the File Types list.
>
> I've hunted thru the Registry, scoured the KB, and have simply run out of
> ideas. Can anyone tell me how to undo a device association to a particular
> program?

associate.exe from the Windows Resource kit has a switch do
undo associations:

Registers or Unregisters a file extension operating system shell.
ASSOCIATE .ext filename [/q /d /f]
.ext Extension to be associated.
filename Execuatble program to associate .ext with.
/q Quiet - Suppresses all interactive prompts.
/d Delete - Deletes the association if it exists.
/f Force - Forces overwrite or delete without questions.
Examples:
Associate .Lst NotePad.Exe
Adds the association of .Lst with Notepad.Exe.
Associate .Lst /d
Deletes the association of .Lst from Notepad.Exe.
Associate .Lst
Returns the association for .Lst if it exists.
Return Value:
A return value of zero indicates success.