On 7 Oct 2004 18:15:19 -0700, (Mark Mestman)
wrote:

Probably you can go to the preferences menu in photoshop and deselect
the file types you don't want photoshop to try to open by default.

Hope this helps

Or, if in WIndows XP -- My Computer View Folder Options
File Types

Scroll down to the "JPEG Image" icon(s) -- there may be more
than one such for different jpeg filetype extensions. Use the Edit...
button to go in and reassign the program association to your taste.