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 ...

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 ...

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 ...

1How to view file name extensions for all files on a Mac 2How to view file name extensions for a individual file on a Mac The default setting for Mac OS is to not display a file's extension. For those ...