What everybody should know about file extensions and associations
This isn’t a new topic and some readers may wonder why I’m posting about it. Power users may know all about the subject but there are tens of millions of PC users who do not know many of the elementary things about Windows that they should. File extensions and associations constitute one of those neglected areas. I’ve discussed this subject in some detail over at my beginner’s site. Maybe I can entice some of my less experienced readers to look into this important area by giving a quick summary of what it’s about.
In Windows, a very important part of a file’s name is its extension. The extension is the part after the dot. It is often, but not always, three characters. It is very important because the file extension tells Windows what kind of file it is. Thus, .txt tells Windows that the file is a text file, .mp3 tells Windows that the file is a certain type of media file, and so on.
Once Windows knows what kind of file it is dealing with, the operating system then knows what software it is supposed to use to open the file or to edit it or do whatever action is called for. Generally, an extension will have some particular program that is assigned to open files with that particular extension. The program is said to be associated with that file type. Thus, when you click on a file somefile.txt, Windows knows that it is supposed to open the file with Notepad or whatever text editor is associated with text files on your particular computer. One reason for knowing about this stuff is so you can recognize a common problem that people have when the wrong (or no) software is associated with some file extension.
Because file extensions and associations play such a central role in how Windows handles files, even average PC users should be aware of them. Unfortunately, Microsoft likes to hide file extensions. I, and many much more important computer people, have been railing about this for years. In a previous post, I said:
Microsoft also has a thing about hiding file extensions. Ever since the beginning of Windows, the default setting for file extensions has been to hide them. Over the years many computer experts have pointed out over and over that this is not the best choice. Microsoft has never budged and it looks like Vista continues this practice. Changing the settings so that you can see file extensions is not that difficult.
You can see the procedure for making file extensions visible in Windows XP at this simple tutorial. The procedure for Vista is given here.