Why Windows File Explorer No Longer Previews Certain Files: A Key Security Upgrade
If you’re an avid Windows user, you’re likely familiar with the convenience of the File Explorer’s preview pane. It lets you peek at the contents of images, documents, and other files without having to open them. However, you may have recently noticed that certain file types no longer generate a preview. This isn’t a bug—it’s a deliberate and important security enhancement from Microsoft designed to protect your system from harm.
This change directly addresses a sneaky and dangerous type of cyberattack that exploits the very act of previewing a file. Here’s what you need to know about this crucial update and how it makes your computer safer.
The Hidden Danger in File Previews
On the surface, previewing a file seems harmless. You aren’t executing a program or opening a document, so what’s the risk? The danger lies in how the preview is generated. To show you a glimpse of a file, Windows uses special programs called preview handlers. If a vulnerability exists in one of these handlers, a cybercriminal can craft a malicious file to exploit it.
This means that simply selecting a rigged file to view its preview could be enough to execute malicious code on your system. This type of “zero-click” or “low-interaction” attack is particularly insidious because it doesn’t require the user to fall for a phishing scam or knowingly run a suspicious program. The attack can happen quietly in the background, triggered by an action as simple as navigating through a folder.
Microsoft’s Proactive Step to Bolster Security
To combat this threat, Microsoft is disabling the preview functionality for a specific set of file types that are frequently abused by attackers. This is a targeted, proactive measure to close a potential loophole before it can be widely exploited.
The files that are no longer being previewed are typically those that contain executable code or scripts, including:
- Batch files (
.bat,.cmd) - PowerShell scripts (
.ps1) - JavaScript files (
.js) - Visual Basic scripts (
.vbs) - Installer files (
.msi) - Registry files (
.reg)
These file types are powerful tools for system administrators but are also favorite weapons for malware authors. By preventing Windows from automatically trying to render a preview of these files, Microsoft effectively shuts down this specific attack vector.
What This Means For Your Workflow
For the vast majority of users, this change will have little to no impact on daily productivity. Most people don’t need or want to preview the code inside a batch file or a PowerShell script. Instead, the blank preview pane now serves as a subtle but useful security indicator. It signals that you are dealing with a potentially powerful file that should be handled with care.
The core benefit is a significant reduction in your system’s “attack surface”—the number of ways a hacker can try to gain entry. This is a classic example of security over convenience, where a minor change in functionality provides a major boost in protection. You can still open, edit, and run these files as you normally would; you just can’t peek inside them from the File Explorer pane.
Actionable Security Tips to Keep Your System Safe
This update is a great step forward, but it’s just one part of a comprehensive security strategy. To keep your computer secure, always follow these best practices:
- Keep Windows Updated: This security fix, like many others, is delivered through Windows Update. Ensure your system is set to automatically install the latest updates to receive critical protections as soon as they are available.
- Be Cautious with Downloads: Never open files or email attachments from unknown or untrusted sources. Even if a source seems legitimate, be skeptical of unexpected files, especially scripts and executables.
- Use Reliable Antivirus Protection: Make sure you have a robust antivirus program running and that it is kept up to date. Windows Defender, built into modern versions of Windows, is a strong, free option.
- Show File Extensions: In File Explorer’s “View” settings, enable “File name extensions.” This helps you spot fake files, such as a malicious program named
invoice.pdf.exethat is pretending to be a document.
Ultimately, Microsoft’s decision to restrict risky file previews is a welcome and intelligent security upgrade. It’s a behind-the-scenes adjustment that makes your everyday computing experience safer without getting in your way, reinforcing the critical importance of a layered, proactive defense against ever-evolving cyber threats.
Source: https://www.helpnetsecurity.com/2025/10/24/microsoft-blocks-risky-file-previews-in-windows-file-explorer/
