File Associations
Associating a program with a file type is important because that is the default program used to
open the file when you double click on it in both Windows and the Mac OS. Most files/documents have default associations but sometimes you will want to change them (e.g. because you don’t use the default program to read them) or you will come across a file/document without an association.
In Windows you do this in the Windows Explorer by choosing Tools -> Folder Options and then the File Types tab. After usually a significant wait you will get a list of file extensions and the associated file type. Click on one of them and at the bottom of the pane you will see the “Details” for the extension, showing the program that opens it. Click on the Change… button and you will get a popup window with recommended programs, other programs and a Browse button where you can navigate to a different application. There is also a check box that you can click to always use the selected program to open this kind of file.
On the Mac it isn’t as easy to find the place to make this change but the functionality is similar. In the Finder select a file/document of the type that you want to change. Then open the Info window by either typing in Command-I or selecting File -> Get Info. About 3/4 of the way down the window that comes up will be a section that is entitled Open With. The pull down menu in this section will show the current default, recommended alternatives, and there is an Other… choice that lets you browse to any application you want. If you select something other that the current default then the Change All… button becomes active. Click on it and you can confirm the change (or cancel).
The Mac method is quicker when you have a single file type you are changing. However, say you have just installed a new application that can open several file types (e.g. a media player). Often these applications will offer to change the associations for you but not always. There is also the case where you change the associations but decide that you don’t like the new program and want to change them all back. Now you have to search around for files of the different types and make the changes one at a time. Perhaps you don’t even have files with all the types (but, of course, you’ll get one in the next couple of days) and then you are out of luck.