How to Show File Extension in Windows 7

Open Windows Explorer, you can do this by opening up any folder or you can just click Start > User Name.

Click “Organize”, scroll down and click “Folder and search options”.

Click the “View” tab. Scroll down until you see “Hide extensions for known file types”, un-check this line here by clicking on the check box.

Click “OK” and now your file extensions will now longer be hidden.