How to I append excutable files?

[junppplus]

I made some application to excute other files.

For example my application makes a xml files.

And I want to execute it when I double click the xml files.

How to I do that?

[RobertDickau]

What type of project are you using (Basic MSI or InstallScript)? MSI exposes this kind of file-extension association in a component's advanced settings (and also in the Project Assistant), where InstallScript requires writing directly to the registry.