The File Masking Vector
By default, Windows 11 intentionally hides the three- or four-letter extension at the end of a filename (such as `.docx`, `.jpg`, or `.exe`). Microsoft implemented this to prevent novice users from accidentally deleting the extension when renaming a file, which breaks the operating system’s ability to know what program to open it with. However, this is a massive security vulnerability. A malicious actor can easily name a virus `Invoice.pdf.exe`. Because Windows hides the final `.exe`, the file will appear to the user as a harmless `Invoice.pdf` document.
How to Show File Extensions
You must instruct the File Explorer to globally reveal the true, raw filename of every single item on your hard drive, allowing you to visually verify its actual format before double-clicking.
1. Open the File Explorer (click the yellow folder icon on your taskbar or press the Windows Key + E).
2. Look at the modernized command bar at the absolute top of the window.
3. Click the View button (it is accompanied by a small list icon).
4. A dropdown menu will appear. Hover your cursor over the very bottom option: Show.
5. A secondary fly-out menu will appear to the right.
6. Click on File name extensions.
7. A checkmark will instantly appear next to the option, confirming the global override is active.
The interface will immediately refresh. Every file in your system will now proudly display its true suffix. A photo will no longer just be named “Vacation”; it will explicitly be named `Vacation.jpg`. If you ever rename a file, ensure you do not delete this suffix.