Why "Application Not Found" ?

[Stumped in Exeter]

It used to be that when I received an attachment in Microsoft Outlook, I
would just click the "Open" option and the attachment would open. Now when I
click on an attachment and choose "Open" (as opposed to Save) I get a dialog
box that says "Application Not Found" and so I have to choose the "Save"
option and put it in a folder. Then when I go to the folder, the image (it's
usually an image) is there. What have I done that I now can't open an
attachment right away.

 

[VanguardLH]

It used to be that when I received an attachment in Microsoft Outlook, I
would just click the "Open" option and the attachment would open. Now when I
click on an attachment and choose "Open" (as opposed to Save) I get a dialog
box that says "Application Not Found" and so I have to choose the "Save"
option and put it in a folder. Then when I go to the folder, the image (it's
usually an image) is there. What have I done that I now can't open an
attachment right away.

What happens when you double-click on that saved image file? Does a
program load to display the image? Or does nothing happen (other than a
dialog appearing asking you to select a program to use as the handler to
open that image file)?

What is the filetype of the attached file? From that, what program is
configured as the handler for that filetype? That is, what program do
you have installed that should open that file of that type?