File Explorer Preview Not Working After Windows Update
Overview
Microsoft recently released a Windows security update that changes how File Explorer handles files downloaded from external sources (such as email attachments or the internet).
As a result, some files may no longer display a preview in the File Explorer preview pane.
This is expected behavior and not an issue with your computer.
Why This Is Happening
With this update, Windows applies a security tag (also known as “Mark of the Web”) to files originating from external sources. These files are treated as untrusted to help protect your system.
Due to this security enhancement, File Explorer may block previews for these files to reduce the risk of malicious content being executed automatically.
What This Means for You
- Files downloaded from email, websites, or shared platforms may not show a preview
- This behavior is part of Microsoft’s security model
- This may impact common file types such as PDFs, Word documents, and images
Current Status
At this time, there is no consistent or supported method to restore preview functionality for affected files.While some manual workarounds may exist in limited cases, such as right-clicking the file and Unblock (if available), they are not reliable and may lead to inconsistent results.
For this reason, we are not recommending or supporting those approaches.
Important
We follow Microsoft-supported configurations to ensure system security, stability, and long-term reliability.
- We do not disable or bypass Microsoft security updates
- Unblocking files individually is the only supported method at this time
We will continue to monitor Microsoft’s guidance and provide updates if a supported solution becomes available.