---
title: "HideFileExt 0: always show file extensions in File Explorer"
description: "By default File Explorer hides endings such as .exe, .bat and .pdf. What the tweak changes, when it helps, when it hurts and how to undo it."
url: https://frozentweaks.com/tweaks/show-file-extensions
author: Frost LIVE, Founder of Frozen Tweaks
published: 2026-10-08
updated: 2026-10-08
category: "Security"
source: Frozen Tweaks (https://frozentweaks.com)
---

# HideFileExt 0: always show file extensions in File Explorer

**Short answer:** By default File Explorer hides endings such as .exe, .bat and .pdf. HideFileExt set to 0 shows them, so a file named 'settings.pdf.exe' cannot pass as a document. In the registry it sets HideFileExt to 0 under HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced.

## In the app

- Switch: Show File Extensions (Security, Free, Standard)
- Undo: Yes. Switching it off puts back exactly what was there before, value for value.
- Catalog row: https://frozentweaks.com/tweaks#t-1160

## What it does

By default File Explorer hides endings such as .exe, .bat and .pdf. HideFileExt set to 0 shows them, so a file named 'settings.pdf.exe' cannot pass as a document.

In the app the switch is called "Show File Extensions", described there as: Shows endings like .exe and .bat in File Explorer, so a program cannot pose as a document.

## When it helps

- Spotting fake downloads, which matters when you download configs, mods and tools.

## When it hurts

- Nothing, though renaming a file now shows the ending, so take care not to delete it.

## What it writes

Read from the app's source. "Switching it off" is what the app writes when you turn the tweak off again.

Registry values:

| Key | Value | With the tweak | Switching it off |
| --- | --- | --- | --- |
| `HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced` | `HideFileExt` | `0` | Your previous value (saved before the change, or deleted if there was none). Windows default: 1 |

Source: Tweaks/pack_extra.hpp in the app's source, app 2.0.0, checked 2026-10-08.

## The same change by hand

Run in a Command Prompt opened as administrator. Make a restore point first.

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

Put it back:

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

See what it is set to now:

```bat
reg query "HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced" /v "HideFileExt"
```

## How to undo it

Switch the tweak off in Frozen Tweaks. The app saved what each value was before the change and writes exactly that back, or removes the value if it did not exist.

## Verdict

Recommended for everyone. It is a small habit that prevents real mistakes.

## Questions

### What does the "Show File Extensions" tweak change in Windows?

In the registry it sets HideFileExt to 0 under HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced.

### What is the default value of HideFileExt?

The Windows default of HideFileExt is 1. Frozen Tweaks sets it to 0, and switching the tweak off puts back the value you had before.

### Is "Show File Extensions" safe to switch on?

Recommended for everyone. It is a small habit that prevents real mistakes. The main cost: Nothing, though renaming a file now shows the ending, so take care not to delete it.

### How do I undo it?

Switch the tweak off in Frozen Tweaks. Switching it off puts back exactly what was there before, value for value.

### Is "Show File Extensions" free in Frozen Tweaks?

Yes. It is one of the free tweaks, with no time limit.

## Related guides

- [Is PC Optimization Software Safe? What to Check Before Installing](https://frozentweaks.com/guides/is-pc-optimization-software-safe)
- [Windows 11 Gaming Optimization: What Still Works in 2026](https://frozentweaks.com/guides/windows-11-gaming-optimization)

## More tweak explainers

- [Recent files in Quick Access](https://frozentweaks.com/tweaks/disable-recent-files-quick-access)
- [Find my device](https://frozentweaks.com/tweaks/disable-find-my-device)
- [App diagnostics access](https://frozentweaks.com/tweaks/block-app-diagnostics-access)

---
Written by Frost LIVE, founder of Frozen Tweaks. Canonical version: https://frozentweaks.com/tweaks/show-file-extensions