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Displaying File Name Extension in Windows

A Windows filename has two parts:

1. the main filename -- e.g., mydoc.txt
2. the filename extension -- e.g., mydoc.txt

Windows uses the extension to determine what the default action on a file will be when, for instance, you double-click on its icon. For example:

Windows is set by default to not show extensions on filenames. This is done presumably to make lists of files less cluttered to read -- a definite plus.

Although it is very important to know what kind of file a file is, most of us are familiar with the icons of many files and don't think we really need to see the extensions to know that a Word file's icon has a big blue "W" in it and an HTML file's icon has a big blue "e" in it.

However, many of us are not familiar with the blue scroll of a .vbs file or the yellow scroll of a .js file. This is important, because the current round of virus/worm attacks on Windows machines by script attachments use filenames like

loveletter.txt.vbs

If you can't see the ".vbs" extension because Windows has hidden it -- or don't notice or recognize the icon, you will probably assume this is a harmless text file that will open in Notepad if you double-click it. And VBS and JS files can be quite dangerous if they're designed to be.

So the slight clutter of visible filename extensions might be a small price to pay for the added security of understanding what's happening on your machine.

If you want to try displaying them (you can always change the setting back to invisible):

1. Go into Windows Explorer.
   If you don't have a toolbar or shortcut (usually a file folder with
   a magnifying glass superimposed over it) to get there, you can
   1. Choose Find from the Start menu
   2. Choose Files and Folders from the side menu
   3. Make sure "C:" is in the Look In box
   4. Type "explorer.exe" in the Named box
   5. Click the Find now button
   6. Double-click "Explorer" when it appears in the lower window
   7. Click OK

2. In Windows Explorer, choose Folder Options from the Tools menu
   (If you have Explorer version 4.0, you won't have a Tools menu --
   instead, choose Options from the View menu )

3. Click on the View tab

4. Find "Hide File Extensions for Known File Types" and UNcheck its box.