Registry Key to Show File Extensions in Windows

This article explains the exact Windows Registry setting that controls whether Windows Explorer hides or displays known file type extensions. By modifying a specific DWORD value within the Registry Editor (regedit), you can configure Windows to always show or hide file extensions such as .txt, .exe, or .docx for the current user.

The Registry Entry Details

The setting that governs file extension visibility in File Explorer is defined by the following registry entry:

• Registry Path: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
• Value Name: HideFileExt
• Value Type: REG_DWORD (DWORD 32-bit Value)

Value Data Settings

The HideFileExt DWORD accepts two values:

• 0: Shows known file extensions (file extensions are visible in Explorer).
• 1: Hides known file extensions (Windows default behavior).

How to Change the Setting via Registry Editor

1. Press Windows Key + R, type regedit, and press Enter to launch the Registry Editor.

2. In the address bar at the top, paste the following path and press Enter:

   HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced

3. Locate HideFileExt in the right-hand pane.

4. Double-click HideFileExt to open its edit window.

5. In the Value data field:

   • Enter 0 to make file extensions visible.
   • Enter 1 to hide file extensions.

6. Click OK.

Applying the Changes

After updating the registry value, the change may take effect immediately, or you may need to refresh File Explorer:

1. Press Ctrl + Shift + Esc to open Task Manager.
2. Locate Windows Explorer under the Processes tab.
3. Right-click it and select Restart.