Clear and Reset Thumbnail Cache in Windows 10  

Thanks. It seeps to be happening only with MP4 files. I looked through a bunch of JPEG files and they seem to be OK. These files are in the "This PC/downloads" folder, and on an external hard drive - so, seems to be all MP4s.

The files on the new La Cie hard drive were just transferred there, so seems like those would be generating thumbnails for the first time when folders are opened on the new external drive - even there it is generating a bunch of duplicate thumbnails - so, instead of MP4s having the correct thumbnail they used to have, they have duplicate thumbnails for a bunch of MP4s - the content and name are still there.

As noted, the computer is also new as of a couple days ago and these files were transferred with Zinstall. TKS

Brink said:

Hello dmholck, and welcome to Ten Forums.

Is this happening to all image files in File Explorer, or only to specific file types?

In addition, is this happening everywhere in File Explorer, or only in a specific location?

Not sure what dmholck is experiencing, but I share his frustration with the thumbnail thing. I had to download Iarcos software to get my picture thumbnails to show. But nothing has aided me in getting ANY PDF thumbnails, or most Office application documents to display thumbnails. And having thousands of files, as many of us do, having to go back a rename them so that we can find them, is somewhat daunting. I wish that someone, ANYONE, would come up with a solution for this. It's not native to Windows 10. It's the result of an update. A recent update. But going back to that particular update, again, requires a bunch of work that we just feel should be unnecessary.

Jes' sayin'....

Moving them to another folder or to the desktop did not change anything.

It seemed that I had the problem that started this thread, which was some kind of corruption in the thumbnail database and we needed to find a way to delete the database and then have Files Explorer rebuild it - never found a way to do it as the suggestions above did not work.

New MP4s are generating thumbnails; they ALL have thumbnails, just not the right picture. I checked a couple of the ones with duplicate pictures; one from back in JUL 2018, but the other one from FEB 2020. But I guess none of the MP4s with duplicate picture are from before the MP4s migrated to the new computer.

What about that original idea that the thumbnail database/cache has to be deleted and rebuilt? ...no good?

- - - Updated - - -

Sorry; said that wrong;
But I guess ALL of the MP4s with duplicate pictures are from BEFORE the MP4s migrated to the new computer.

Thanks. I note again; I did all 3 of the clearing thumbnail cache methods in the tutorial several times and they do not work. It certainly seems logical that clearing the database should be the answer, but on the latest version of Windows 10 (with latest updates), none of those methods worked to clear the database (neither of the 2 batch files or the disk cleanup method). Is there some other way to actually find these database cache files to manually clear them? Maybe a way to search for these files? ...do they have a unique file extension? Would a third party codec package help?

I moved around MP4 files to different folders etc. to no effect. Which MP4 files show the wrong thumbnail picture has changed over time; a folder that had 2 or 3 wrong thumbnails may now have 10 MP4 files that are showing that same wrong picture.

I can't see it, but I'm no expert. Your original corrupted database/cache makes the most sense to me... everything about it seems to explain all the symptoms. Even the "windowscentral.com" forum makes the same observations about the thumbnail database.
Can you think of any explanation as to why none of the thumbnail database clearing methods seem to do anything? Every time you open a folder in the files explorer it "regenerates" the thumbnails of course (in the case of my mp4 files, briefly showing the icon for my default player "MPC-HC X64", but I see no evidence that the database/cache was ever cleared.
What about the mp4 file itself would cause one file to display the picture from another mp4 file, or multiple files to display the picture from 1 other mp4 file?