Overview
By default, Windows will hide known extensions. This causes issuses with duplicate extensions, e.g. filename.txt.txt, and simply not knowing the extension itself. The following article will show you how to reveal the extension in file explorer eliminating these problems.
Option 1 - Update from File Explorer
- While in a folder in File Explorer, open the View menu
- In the "Show/hide" section, check the box for "File name extensions"

- If you cannot find the View menu or on Windows 11, try option 2 below
- From the start menu, search for "File Explorer Options" and open it
- On the View tab and under "Advanced settings", look for and uncheck "Hide extensions for known file types"
- Click OK to save
