Associating multiple programs with extension

Question

I have software that for a sake of example will call A. A - have more then one version of it:

• A 1.0
• A 1.1
• A 2.0

All of these versions can be installed and coexist - meaning higher version is not upgrading lower version. An file extension .aaa is being associated with all 3 programs, meaning that A program saves it files in files with extension .aaa and when .aaa extension being double clicked, latest installed software is being triggered.

Now I am facing a following problem:

• User installs A of version 1.1.
• After a while user installs A 2.0.
• User works with A 2.0 and produces save files with extension .aaa
• User uninstalls A 1.1 User double clicks the .aaa extension file, and receives a popup to find software to open file with (meaning that after uninstalling A 1.1, file extension looses association).

Component ID's and file names of executable files of A are different and upgrade code and program id's are as well of course. Yet, how come after uninstalling lower version of it breaks the association and how can I make it work?

Answer 1

The placement of the registry value is the same between the two versions of 'A' so you should be using the same GUID for the component. Some good rules to follow can be found at: Change my component GUID in wix?

Grab the GUID of the component for the file extension entry from A 1.1 and use it in A 2.0. This should allow the extension to stay after removing A 1.1.

Side Note: This may open the door to needing to manage what version of the application should it open when multiple versions are installed. Example, if you install A 2.0 then A 1.1, your file extension will probable open the file in A 1.1.