How to show image file extensions?
By default, file extensions for known file types are hidden in Windows XP and Vista. You can change this setting so that file extensions are shown for files in a certain folder or for all files. To show file extensions, (1) Open Windows Explore (pressing Windows Key + E) (2) Select “Folder Options…” from the Tools menu and click the View tab. (3) Find the option “Hide extensions for known file types.” and uncheck that. (4) Click the “Apply to All Folders” button and click OK. Note: This setting is system wide, so unchecking this box will make file extensions appear in all folders.