Windows XP provides an option to hide the extensions and also hidden files. To uncover the file extensions the following steps has to be followed.
Click on My Computer and followed by the tools menu (there are also other ways to access tools menu)
Click the Folder options menu
Under Hidden files and Folders, select Show hidden files and folders. And to also Un Check the Hide extensions for known file types. Now all the hidden files will be displayed and also all the known files extension. This should prevent users from launching malicious virus application by mistake.