Open File Explorer, select View → Show → File name extensions.
Step by Step
- Open File Explorer.
- Select View on the toolbar.
- Point to Show.
- Select File name extensions.
- Windows will now display extensions at the end of filenames.
If That Doesn't Work
- If you do not see the View menu, maximize File Explorer or use the three-dot menu/options available in your Windows build.
- For a specific file, right-click it and choose Properties to see its file type.