How to Show File Extensions in Windows 7
File extensions are hidden by windows 7 as a default setting, we can show them as well, just follow these:
1. Clicking the Start button, and then select Computer
2. Press <Alt>, you will see a menu
3. Select Tools->Folder Options, select the view tab.
4. To show file extensions, Check the box
Hide extensions for known file types
We can open the folder options by Control Panel -> Appearance -> Folder Options -> Show hidden files and folders