Not able to view files in explorer via preview pane receiving a message "the file you are attempting to preview could harm your computer. If you trust the source you received it from, open it to view its contents'

Question

I have previously been able to view files including pdf files through window explorer using the preview pane and without opening the file. Since October 2025 l am not able to use this feature anymore l am receiving the following message "the file you are attempting to preview could harm your computer. If you trust the source you received it from, open it to view its contents"

Is there anyway to get this fixed as it is slowing my work productivity.

Thank you,
Tonia

Answer 1

Hello

Correct, this is an intentional security change since the Oct update.

You can read more about it here: 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

You can follow the last section titled "How can I override or unblock this behavior?" to change it.

Answer 2

The message you are encountering when trying to preview files in Windows Explorer indicates that the system is warning you about potential risks associated with opening certain file types. This behavior is a security feature designed to protect your computer from potentially harmful files.

To resolve this issue, you can try the following steps:

1. Check your security settings: Ensure that your security settings in Windows are not overly restrictive. You may want to adjust the settings related to file previews or check if there are any specific settings for the file types you are trying to preview.
2. Modify the registry: If you are comfortable with it, you can modify the registry to change how Windows handles these warnings. However, be cautious, as incorrect changes to the registry can cause system issues. Always back up the registry before making changes.
3. Update your software: Ensure that your Windows and any relevant applications are up to date. Sometimes, updates can resolve issues related to file handling and security warnings.
4. Trust the source: If you trust the source of the files, you may choose to open them directly instead of using the preview pane. This will bypass the warning message.

If these steps do not resolve the issue, you may need to consult with your IT department or seek further assistance from Microsoft support.

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References:

• Enable or disable hyperlink warning messages in Office applications