A file extension, or file name extension, is the letters immediately shown after the last period in a file name. For example, the file extension.txt has an extension of .txt. This extension allows the ...

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 ...

New installations of Windows hide all file extensions, except for Windows components, that would appear in Explorer or an application dialog box that displays file names. File extensions are ...

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 ...