How to Show File Extensions in Windows

By default, file extensions for known file types are hidden in Windows XP. However, you can change this setting so that file extensions are shown for files in a certain folder or for all files on your hard disk.

Steps

1.   Open any folder on your hard drive. It could be your Documents folder, Pictures, Videos, Computer, etc.

2.   Select the "Folder Options" tab from the Tools menu. A new window named "Folder Options" will appear.

3.   Click the View tab. This will show the file and folder view settings.

4.   Uncheck "Hide extensions for known file types". Then click Apply then OK to save the changes.