File name extensions are how OS X recognizes file types, and changing the extension is one way to associate a file with a different program. Sometimes, however, changing the file extension does not ...

Have you ever noticed how your computer knows which program to open when you double click on a file? It doesn’t always know but most of the time it does. When it doesn’t know, your computer will ask ...

In the Mac OS it is possible to change the default program the operating system will use to open a file when you double-click on it. After you have changed this file association, though, you may want ...

Microsoft uses file associations to set default programs for opening different file types on all its operating systems. As a result, when you open a file, be it text, image, or document, on your ...

BearPup sometimes wants to open a file in one program, and other times open it in another. He asked the Answer Line forum for an easy way to do this. Windows uses a file’s extension–the part of the ...

When you double-click a file on your computer, Windows may launch an application to run or display the file. Windows knows how to do this because it maintains a list of known file types and the names ...

When you open files that have a particular file extension, Windows will look at its configuration to determine what the default program should be in order to work with these files. The default program ...

Red Eye Rose received a file with a strange extension. She doesn’t know into what program she should load it. Neither does Windows. I doubt that anyone knows all of the file extensions used since the ...