Always show file extensions — via Mauro Huculak, Pureinfotech

Registrylow riskWindows 11Windows 10

Windows hides extensions like .exe and .pdf by default, which makes it easy to be fooled by a file called "invoice.pdf.exe". Showing them is one of the simplest safety tweaks there is.

Restart Explorer (or sign out) to see it

The easy way

  1. The easy way: in File Explorer choose View → Show → File name extensions.
  2. Or: Settings → System → For developers → File Explorer → Show file extensions.

Registry change

Download apply .reg Download undo .reg

Double-click a .reg file and confirm to merge it. Right-click → Edit first if you want to read it, which is always a good idea with any .reg file from the internet.

Apply

Windows Registry Editor Version 5.00

; Oddbyte.Me: Always show file extensions

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced]
"HideFileExt"=dword:00000000

Undo

Windows Registry Editor Version 5.00

; Oddbyte.Me: undo Always show file extensions

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced]
"HideFileExt"=dword:00000001

Same thing from a command prompt

Run in a normal (non-admin) Command Prompt or Terminal.

reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced" /v "HideFileExt" /t REG_DWORD /d 0 /f

Undo:

reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced" /v "HideFileExt" /t REG_DWORD /d 1 /f

Sources

Source reviewed
2026-11-02
Link checked
2026-11-02
Tested hands-on
Not by Oddbyte.Me

Oddbyte.Me hasn't tried this on every Windows build, so keep the undo handy.

file extensionsexplorersecurityhidefileext

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