SHOW FILE EXTENSIONS

By default, Windows suppresses file extensions. This allows virus writers to make use a double extension ruse to fool users. (For this reason, any attachment with a double extension should be considered infected and the email should be deleted). To properly determine the extension of a file, make sure you have file extension viewing enabled:

In Windows 95/98/NT, open Windows Explorer and select Tools | Folder Options. Click the View tab, select "Show all files" and deselect (uncheck) "Hide file extensions for known file types".

In Windows XP, open Windows Explorer and select Tools | Folder Options. Click the View tab, select "Files and Folders" and deselect (uncheck) "Hide file extensions for known file types".

In Windows 2000, open Windows Explorer and select Tools | Folder Options. Click the View tab, select "Show hidden files and folders" and deselect (uncheck) "Hide file extensions for known file types".