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 ...

Mac OS X computers use a default application to open every file type based on its file extension. If you don't want to use the default application when opening a file, you can select "Open With" from ...

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 ...

One of our readers reported that all the file extensions have changed to some unknown file format. If so, it could be a virus! If a virus has changed all the files extensions to unknown applications, ...