25H2 Windows update prevents preview pane from working. RIDICULOUS!

Question

25H2 Windows update prevents preview pane from working. RIDICULOUS!

Noah Perry 110

I know I'm not the only one now suffering with the Windows 25H2 update, which now renders the preview pane in Windows Explorer basically useless for ANY PDF's that have been attached to an email I receive. When I drag the attached PDF's to a folder, I can't preview it without opening it. I get the message "the file you are about to open my be harmful. If you trust this then open it", or something to that effect. I understand there may be security concerns, but there should be a MUCH easier fix to shut this off. Currently you have to right click the PDF, go to properties, then go to the bottom of the properties window and check the 'unblock' box, but even then it takes 15 seconds for it to be viewable in the preview pane. Even after I've opened a PDF several times, it still shows that message in the preview pane. There should be a basic check box in the windows folders settings to simply shut this off. I go though HUNDREDS of pdf's a day, and I have to do it quickly, and the preview pane allows me to get the info I need at lightning speed. But now having to open all of them will and several minutes to each day, adding up to something like 5 hours a year in wasted clicking. And right clicking PDF's to get to the properties to check the 'unblock' box take too much time too (as mentioned above). What a nightmare. Did MS not thing about the potential for grinding workflows to a halt?

Viorel 127.3K Reputation points

2025-11-20T07:36:24.4966667+00:00

Nevertheless, the hatred should also be directed against the attackers.
Mark Hostettler 25 Reputation points

2025-11-25T16:47:10.23+00:00

This effects a lot of people. The biggest impact to my clients is that they use "Scan to email" to scan documents to themselves. All files that were scanned this way are now blocked, from the past x years. I have even had issues with scan to directory files being blocked. There is no easy way to mark all of those historical files, most solutions are on a file by file or directory basis. I have thousands of files in hundreds of directories. Also, an new files now have to be handled an additional time to allow for this. MS could make it so that emails originating within an organizations are automatically marked safe, and provide us a means to mark all files within a given directory tree as safe. At least help us mitigate the impact of this "improvement". Yes anger is also directed at the hackers, but someone should think through the impact and provide tools to prevent major crisis within legitimate organizations.
Noah Perry 110 Reputation points

2025-11-25T22:11:29.4333333+00:00

Thanks for the reply Mark. Yes, there should be an easy way to make document 'safe' if sent not just within but by an outside organization. I even get this warning message from word docs that I created myself on our server! It's never been sent or received by anyone. That's just ridiculous.
Mark Hostettler 25 Reputation points

2025-12-01T17:45:02.4133333+00:00

I am testing two registry entries. The first prevents the new context window from being displayed, I always end up using the "Show more options" doubling the needed clicks and time to get things done. Also, when adding items to the context windows (next entries) you won't have to use the "more options".

https://learn.microsoft.com/en-us/answers/questions/2287432/(article)-restore-old-right-click-context-menu-in?page=1&orderby=Helpful&comment=answer-12220414&translated=false#newest-answer-comment

I also added the option to unblock a file/files within a directory or sub-tree to the context window.

While this is not perfect, it is less clicks. A step in the right direction. I would only set this up for trusted users.

https://www.tenforums.com/tutorials/129101-add-unblock-file-context-menu-windows-10-a.html
Lisa Brooks 30 Reputation points

2026-01-06T02:59:34.97+00:00

This is so frustrating. I download hundreds of files from a HIPAA secure site then do a quick preview to sort and see what ones I actually need. Opening every file then closing changes noting, I still can't preview it even after I have opened it once. Individually changing the settings for every file is unacceptable. They need to allow disabling of this one feature or bulk changing the options on mulitple files because as it is, there are now two updates I have had to uninstall and won't be reinstalling.
Noah Perry 110 Reputation points

2026-01-06T17:29:25.05+00:00

Lisa, I agree! Let us run our own risk of 'dangerous' files. They shouldn't make a blanket restriction on PDF's just to cover some folks who aren't paying attention to the sources of these PDF's. Just make a setting to turn off this restriction.
Richard Lewis 5 Reputation points

2026-01-21T16:30:37.7866667+00:00

PDF preview is intermittent & slow to take effect.

IF one has to open file to preview, doesn't that defeat the purpose in security of not previewing?? Dipshit idea!
Noah Perry 110 Reputation points

2026-01-22T22:32:40.3033333+00:00

Agreed Richard!
Fir Marshal Bill 0 Reputation points

2026-04-27T00:11:39.2166667+00:00

The problem for me was that ALL extensions - TXT, PDF, JPG, DOC and XLS, all of which used to work before I left for a 6-month vacation, were broken, I left in October. I tried every one of these prescriptions without a remedy. Nothing worked. It infuriated me that the Unblock option was nowhere to be found. Tried the script to humor it - did not work. Finally, I went back to an image I had made in September 2025 and locked down all further Windows updates. Works like a dream now. Wasted enough time.

The idiots at Microsoft should give those who know what they are doing the option to turn the annoying, bloody thing off. This one-size-fits-all crap makes me want to go to a Mac, but that is too drastic! I don’t need Microsoft babysitting me and dictating to me what I can or cannot do. Give us the option and the credit for half a brain!
Pauline Sallee 0 Reputation points

2026-09-17T18:55:02.74+00:00

Can not help you because I have a similar problem. But I wanted to add that it is unacceptable to think that Microsoft can force an update on my computer that I own, with my purchased security software that works better than Microsoft's, with all of the software purchased, not rented, including my Office packages and that forced update that I can not uninstall can cause problems that disable functions. I would think the FTC would have a problem with that concept. These problems are usually someone not checking their code. When I wrote code I checked it 3 times. Now it seems there is some program, probably written by a lazy code writer that checks and misses a lot! The fact that they can give a "fix" or put out an update to fix means the code was written badly. Everyone needs to file a complaint with the FTC.

4 answers

Your answer

Viorel 127.3K Reputation points

2025-11-20T07:36:24.4966667+00:00

Nevertheless, the hatred should also be directed against the attackers.
Mark Hostettler 25 Reputation points

2025-11-25T16:47:10.23+00:00

This effects a lot of people. The biggest impact to my clients is that they use "Scan to email" to scan documents to themselves. All files that were scanned this way are now blocked, from the past x years. I have even had issues with scan to directory files being blocked. There is no easy way to mark all of those historical files, most solutions are on a file by file or directory basis. I have thousands of files in hundreds of directories. Also, an new files now have to be handled an additional time to allow for this. MS could make it so that emails originating within an organizations are automatically marked safe, and provide us a means to mark all files within a given directory tree as safe. At least help us mitigate the impact of this "improvement". Yes anger is also directed at the hackers, but someone should think through the impact and provide tools to prevent major crisis within legitimate organizations.
Noah Perry 110 Reputation points

2025-11-25T22:11:29.4333333+00:00

Thanks for the reply Mark. Yes, there should be an easy way to make document 'safe' if sent not just within but by an outside organization. I even get this warning message from word docs that I created myself on our server! It's never been sent or received by anyone. That's just ridiculous.
Mark Hostettler 25 Reputation points

2025-12-01T17:45:02.4133333+00:00

I am testing two registry entries. The first prevents the new context window from being displayed, I always end up using the "Show more options" doubling the needed clicks and time to get things done. Also, when adding items to the context windows (next entries) you won't have to use the "more options".

https://learn.microsoft.com/en-us/answers/questions/2287432/(article)-restore-old-right-click-context-menu-in?page=1&orderby=Helpful&comment=answer-12220414&translated=false#newest-answer-comment

I also added the option to unblock a file/files within a directory or sub-tree to the context window.

While this is not perfect, it is less clicks. A step in the right direction. I would only set this up for trusted users.

https://www.tenforums.com/tutorials/129101-add-unblock-file-context-menu-windows-10-a.html
Lisa Brooks 30 Reputation points

2026-01-06T02:59:34.97+00:00

This is so frustrating. I download hundreds of files from a HIPAA secure site then do a quick preview to sort and see what ones I actually need. Opening every file then closing changes noting, I still can't preview it even after I have opened it once. Individually changing the settings for every file is unacceptable. They need to allow disabling of this one feature or bulk changing the options on mulitple files because as it is, there are now two updates I have had to uninstall and won't be reinstalling.
Noah Perry 110 Reputation points

2026-01-06T17:29:25.05+00:00

Lisa, I agree! Let us run our own risk of 'dangerous' files. They shouldn't make a blanket restriction on PDF's just to cover some folks who aren't paying attention to the sources of these PDF's. Just make a setting to turn off this restriction.
Richard Lewis 5 Reputation points

2026-01-21T16:30:37.7866667+00:00

PDF preview is intermittent & slow to take effect.

IF one has to open file to preview, doesn't that defeat the purpose in security of not previewing?? Dipshit idea!
Noah Perry 110 Reputation points

2026-01-22T22:32:40.3033333+00:00

Agreed Richard!
Fir Marshal Bill 0 Reputation points

2026-04-27T00:11:39.2166667+00:00

The problem for me was that ALL extensions - TXT, PDF, JPG, DOC and XLS, all of which used to work before I left for a 6-month vacation, were broken, I left in October. I tried every one of these prescriptions without a remedy. Nothing worked. It infuriated me that the Unblock option was nowhere to be found. Tried the script to humor it - did not work. Finally, I went back to an image I had made in September 2025 and locked down all further Windows updates. Works like a dream now. Wasted enough time.

The idiots at Microsoft should give those who know what they are doing the option to turn the annoying, bloody thing off. This one-size-fits-all crap makes me want to go to a Mac, but that is too drastic! I don’t need Microsoft babysitting me and dictating to me what I can or cannot do. Give us the option and the credit for half a brain!
Pauline Sallee 0 Reputation points

2026-09-17T18:55:02.74+00:00

Can not help you because I have a similar problem. But I wanted to add that it is unacceptable to think that Microsoft can force an update on my computer that I own, with my purchased security software that works better than Microsoft's, with all of the software purchased, not rented, including my Office packages and that forced update that I can not uninstall can cause problems that disable functions. I would think the FTC would have a problem with that concept. These problems are usually someone not checking their code. When I wrote code I checked it 3 times. Now it seems there is some program, probably written by a lazy code writer that checks and misses a lot! The fact that they can give a "fix" or put out an update to fix means the code was written badly. Everyone needs to file a complaint with the FTC.

Answer 1

It seems you're experiencing issues with the preview pane in Windows Explorer after the 25H2 update, particularly with PDF files. While I understand your frustration, the behavior you're describing is often related to security features in Windows that are designed to protect users from potentially harmful files. Unfortunately, the context provided does not contain specific information about the 25H2 update or its effects on the preview pane functionality for PDFs.

To address your concerns, you might consider the following general approaches:

Check for Updates: Ensure that your Windows is fully updated, as Microsoft may release patches that address issues like this.
Adjust Security Settings: You can explore the security settings in Windows to see if there are options that might reduce the prompts you are encountering.
Use Alternative PDF Viewers: If the built-in viewer is causing issues, consider using third-party PDF viewers that might integrate better with Windows Explorer.
Feedback to Microsoft: Providing feedback directly to Microsoft about your experience can help them understand user needs and potentially improve future updates.

For more detailed troubleshooting, you may want to consult Microsoft support or community forums where users discuss similar issues.

References:

Answer 2

Alexandr S 106.4K Independent Advisor

Hello, Noah Perry.

The easiest way is to use the "File Explorer add-ons utility" from the Microsoft Power Toys program.: https://learn.microsoft.com/en-us/windows/powertoys/file-explorer I use this program myself...

Download page: https://apps.microsoft.com/detail/xp89dcgq3k6vld?hl=en-us

Noah Perry 110 Reputation points

2025-11-21T00:23:10.08+00:00

Alexandr, thanks for the reply. Yes, I'm looking at the possibility of PowerToys, but it seems like I will have to always hit ctrl + space or create my own shortcut to use PowerToys 'peek' mode to view a file/PDF. That seems like it takes too much time and too much repetition for me. I can try it, but I'm still perplexed how MS thinks this is totally fine to handcuff people who rely on the preview pane to look through hundreds of documents a day. They should have a setting as part of their latest update to allow us to decide for ourselves if we want this security function on or off. What's also frustrating is that even after you open the pdf, if you try to preview it later you will get the warning message again! It should recognize that you've read the warning and opened it anyway, and after you've opened it once, the warning message should no longer appear for that pdf, in my opinion.
Vanya Bauer 35 Reputation points

2026-01-25T13:44:48.1266667+00:00

This does not solve the problem.

Answer 3

Something strange is happening... After your comment, I decided to check all (if possible) the PDF files that I have on my PC. The result surprised me. About a quarter of the files are not displayed in the Explorer preview area, even though I have completed the Security settings (SmartScreen and Exception settings), as well as unblocked them in the "Properties" of these files. The strange thing is that all the PDFs are downloaded from the Internet. This issue is also much discussed on third-party resources. And here I came across a link: 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

where does Microsoft itself write about the restrictions and in the section "How can I override or unblock this behavior?" the way to disable it. Unfortunately, it didn't work for me either.

P.S. One of the discussions***: https://www.reddit.com/r/Surface/comments/1i5hsr7/windows_file_explorer_preview_pane_fails_on_pdf/

***Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.

Answer 4

Noah Perry 110

Thanks for the info Alexandr. I just don't understand why this cannot be solved by simply allowing a setting that a user can activate or deactivate allowing the user to decide for themselves. We do not need babysitting. Just make a check box like the other million checkboxes that MS Windows, or Adobe, or whoever is responsible for this ridiculous global security setting, has and let the user run the risk. My workflow (and I'm sure hundreds of thousands of other users) is destroyed and it's added hours to my yearly tasks.

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