63. Tutorial for opening
By Mark Alberstat
We recently received this question:
I sometimes receive attachments with my e-mails that I cannot open because
I have not created a file association. Could you address this problem
sometime in your column?
O. David, Dartmouth
In the Microsoft Windows environment, you can graphically see each file in
your computer with a small icon. These icons are supplied by the operating
system to assist you not only in navigating your system, but also
organizing it. The system knows which icon to display next to each file by
reading the file's extension. This is the three-letter designator at the
end of the file name, preceded by a period.
The operating system knows that files that end with .doc are document
files created by Microsoft Word. Unfortunately, not everything is
cut-and-dried, as sometimes different programs will use the same file
extension. When this happens, usually the most recently loaded program
will become associated with file type.
But what happens when you have a file with an extension that the computer
doesn't know or has forgotten how to recognize? You then have to
reassociate the file with a program. When you have a file that has no
association, there is still an icon next to the file name, but instead of
looking like a familiar program icon, it is a white box with the Windows
logo in the middle. This immediately tells you the computer does not know
how to open this file.
To associate a file type with a program, different versions of Windows go
about it in similar but slightly different ways. In general, you have to
open Windows Explorer and click on the View menu item (or Tools, depending
on the version of Windows). Then click on Folder Options and select File
Types. You will then see a list of extensions and their related icons. It
is in this interface panel that you can change or add an association.
To change an association, simply scroll through the list until you find
the one you are looking for, click on it and then hit the Change button.
Another window will appear, listing all the computer's loaded programs.
Choose the program you think will best open this file type and then click
To create a new association, click on the New button, type the
three-letter extension in the appropriate box and click OK. Then find that
new extension in the list and hit the Change button to find the program
that will open this file type.
A problem will arise, however, when you have a file but do not have an
application to open it. An example of this would be receiving a PDF
document but not having Adobe's free reader. Without the proper
application, associating the file with another program will not solve the
problem of a file not opening correctly.
If you are unsure as to which program opens a certain file type, check at
http://filext.com - a site that keeps
track of hundreds, if not thousands,
of extensions and their related programs.
Users should note that if a file does not have an extension, it cannot be
associated with a program. As well, Windows will only associate one file
type with one program. This means Windows cannot associate a .txt file
with both Word and Notepad.
There are programs you can download, such as OpenExpert, that will allow
you to associate multiple programs with a single file type. Most of these
programs work by right-clicking on the file and going to the Open With
menu. It is in this context menu that you will see the applications
properly associated with this type of file.
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Originally published 3 July 2005