Tried the .reg changes to solve the "This file does not have a program associated with it for performing this action. Please install a program or, if one is already installed, create an association in the Default Programs control panel." and it did not resolve mine.
Get that message when trying to click on a picture that will open a .pdf file within an email received in Live Mail.
The Default Program window does not have a program for this type of file, so how do I get one in there?