How can I find out what a file extention of a file is if the extention is hidden?

If you can see the file extensions of other files on your computer, you will need to right-click on the video file and add the correct extension by renaming it. You can always add video-related file extensions to your video file until you get the correct extension. Or, you may be able to use a program such as VLC to view to properties of your video. The properties may contain clues to the correct file extension. VLC can be downloaded from: http://www.videolan.org/vlc/

To see the file extensions for all files on your computer, go “My Computer” => “Tools” => “Folder Options” => “View” and uncheck “Hide extensions for known file types”. If you want to enable this feature in Windows Vista but don’t want to unhide the Menu Bar, go “Computer” => “Organize” => “Folder and Search Options” => “View” and uncheck “Hide extensions for known file types”.

Do any of these ideas help?

Matt,

I must respectfully disagree with your method. Although your method will work if Windows is hiding all file extensions, it won’t work in other cases.

As a test of your method, I deleted the extension from an MP3 file on my computer. All tabs in the Properties window reported the file type as “File”. Worse still, when I added an incorrect file extension, an incorrect file type was reported. For example, I changed the extension on the MP3 file to .wma, and all tabs in the Properties window said the file was a “Windows Media Audio file”.

Even with the incorrect .wma extension, VLC played the MP3 file and gave clues to the correct file extension in “Tools” => “Codec Information”. In my opinion, VLC is still the best way to answer the original question.

Thanks!