How do I get Notepad++ to associate a file type with a language? [duplicate]

I have associated .wxs files with Notepad++. So far so good. However, it doesn't remember that it should use XML syntax highlighting. How do I associate a file-type with a Language?

Solution 1:

As here is mentioned : ASSOCIATE FILE EXTENSIONS WITH SPECIFIC LANGUAGES IN NOTEPAD++ you should do :

In Notepad++ navigate to Settings > Style Configurator…

Choose a language on the left side that you want your own extension to match (i.e. if I want .config files to style like XML then I’d choose XML). In the User ext. field near the bottom, enter in your custom user extension without the dot in front of it (e.g. config for *.config files). Now restart Notepad++ and it will map that new extension to the style you’ve chosen.

NOTE: Make sure you are running Notepad++ using Administrator privileges, otherwise the settings won't be saved when you click "Save and Close".