I can no longer view PDFs in file explorer

Question

I can no longer view PDFs in file explorer - it says '...the file could harm your computer'. From reading other posts i understand this is a new security protocol. However your efforts to provide security protection have made an essential feature unusable. That is not how to protect us... you may as well advise us not to use our computers to stay safe! I know that you can 'unblock' files manually one by one but that is utterly impractical. Please can you advise when Microsoft will be fixing this? Alternatively is there a setting i can change to revert back to being able to view my files? Many thanks

Answer 1

I recommend adding an option to unblock all files in a folder to your Explorer context menu. See:

https://www.elevenforum.com/t/add-unblock-file-context-menu-in-windows-11.2763/

Note: I do not work for Microsoft.

Answer 2

This problem is caused by the October update, initially this was thought to be a bug in that update, however, Microsoft have since indicated on the link below that this is a deliberate security measure added in that October update and they haven ot indicated they will provide a setting to disable this option.

https://support.microsoft.com/en-us/topic/file-explorer-automatically-disables-the-preview-feature-for-files-downloaded-from-the-internet-56d55920-6187-4aae-a4f6-102454ef61fb

This forum is just a user to user forum, the best option would be to open the Feedback App in Windows and provide feedback to their support about this lack of functionality caused by that update.

Answer 3

It seems that the inability to view PDFs in File Explorer is related to a new security protocol that blocks certain PDF files from being opened due to potential risks. This is a part of the security measures implemented by Microsoft to protect users from harmful files. Unfortunately, there is no direct fix mentioned in the provided context regarding when this issue will be resolved or if there is a setting to revert back to the previous functionality.

For now, the only workaround is to manually unblock each PDF file, which can be impractical if you have many files. If you are using Adobe Reader as your default PDF viewer, you might also consider configuring the appropriate Attack Surface Reduction rule to allow it to create child processes, which may help with viewing PDFs more seamlessly.

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References:

• Microsoft 365 issue opening .pdf - Microsoft Q&A
• Essential Eight user application hardening