I am using Windows 7. I installed a media application (KMPlayer) that does not show up in the "Set Default Programs" list. Now in the KMPlayer's preferences, there's a setting to associate file types with itself. But when I tried that, I noticed that the files still default to Windows Media Player. So can I assume that no external application can change the program associated with a file type unless explicitly done via the: [Set Default Programs] or [Associate a file type ... with a program] or the [Open with...] options? Thanks in advance! Btw, I know there are utilities that can help me batch change it. I'm just more curious about the "rules" that Windows 7 has in place regarding file types and their associated programs.