Windows Vista/7 screwed up file associations badly, you can do far less with them than you could under Windows 95. Under Windows 95, you could customize the right click menu for any file type, and add all your favorite programs to that menu as a different option. That's gone since Vista, which added in the buggy "Open With" submenu.

The worst is that today, if you associate Icon files with an icon editor, Icons suddenly lose their ability to display themselves, and instead turn into pictures of the associated application!