SOT: thumbnails on Windows 10

If you mean a (sub)directory that holds photos then just right-clicking on a blank part of the window gives you a popup where the first entry is view >, and this allows you to choose lists, details or icons.

If you mean the directory itself then right-clicking on the directory name and choosing properties gives you a panel where one of tabs allows you to decide what folder icon shows before the directory name

These are examples of storage. They haven't always gone to such gigantic dimension values, so I don't know what's up with that. Some of mine had a few megabytes of material in them.

\Users\Bullwinkle\AppData\Local\Microsoft\Windows\Explorer\thumbcache_idx.db \Users\Bullwinkle\AppData\Local\Microsoft\Windows\Explorer\thumbcache_16.db \Users\Bullwinkle\AppData\Local\Microsoft\Windows\Explorer\thumbcache_32.db \Users\Bullwinkle\AppData\Local\Microsoft\Windows\Explorer\thumbcache_48.db \Users\Bullwinkle\AppData\Local\Microsoft\Windows\Explorer\thumbcache_96.db \Users\Bullwinkle\AppData\Local\Microsoft\Windows\Explorer\thumbcache_256.db \Users\Bullwinkle\AppData\Local\Microsoft\Windows\Explorer\thumbcache_768.db \Users\Bullwinkle\AppData\Local\Microsoft\Windows\Explorer\thumbcache_1280.db \Users\Bullwinkle\AppData\Local\Microsoft\Windows\Explorer\thumbcache_1920.db empty \Users\Bullwinkle\AppData\Local\Microsoft\Windows\Explorer\thumbcache_2560.db empty \Users\Bullwinkle\AppData\Local\Microsoft\Windows\Explorer\thumbcache_sr.db

If I use cleanmgr.exe and scroll down to the bottom, there is a tick box to clear thumbnails, and it will dial the size down to zero for each one.

After you clean them, as long as those files grow in size, your thumbnail cache is working (on the "fill 'er up" aspect of the problem).

Then, that leaves the setting to show icons, as a culprit. It could be that some behavior changed since "File Explorer got tabs".

Thumbnails are a mixed bag.

Some file types have no "Provider", so a thumbnail is not available.

PDF files, the Adobe Acrobat Reader has a "Provider", which registers when you install it. There was some issue with x86 versus x64 version of the software, as to whether that worked or not. This gives thumbnails for PDF files. Examining a PDF is computationally expensive, so you could only process one or two of them per second.

And that's a perfect example of "why have a cache". If the above set of files keep cached copies, then when you open a folder the second time, the PDF thumbnails will be painted from cache, and Acrobat won't have to "wake up".

some image types, Microsoft give the "Provider". A JPEG is an example. I saw in some trace, that "turbo jpeg" libraru was being used. Apparently, the thumbnail generator is fast enough, for smaller files, it is faster for the "Provider" to paint the thumbnail, than for the cache to do it. The cache is that slow.

I gather, from the effort Microsoft puts into deleting the cache files, that there is no compaction mechanism. If you added a file to a picture folder, then deleted it later, the item may still exist inside the cache. Even though there would be no working file reference to hook it to a filesystem file.

As for your general symptoms.

In the last month to six weeks, I've seen a *lot* of flaky and weird behavior in the Microsoft software. I don't know where this is coming from, or why.

It used to be in the past, you did an extra reboot, and that flushed out the flaky stuff. Now, flakes "dribble" into the middle of what you're doing. You'll see out of the corner of your eye, something is f****ng up... and now I just slide a window over top of it so I can't see it :-)

Paul

Can you trace it back to any event? Maybe you need to go back to a restore point before that and see if it fixes the issue. Brian

It is set to large icons. However, the 'icon' displays as the traffic cone of VLC media player rather than as a thumbnail.

I tried that but this offers lots of icon options but not thumbnail.

Thanks. Unfortunately, my IT skills are insufficient to allow me to understand it. However, I thought Windows Explorer supplied the thumbnail.

Are these picture file or video files? Sometimes videos don't seem able to display an icon although many do.

When you try to open a file and Windows doesn't know what application to use, it gives you a list of applications to choose from and a tick box allows you to permanently associate that file type with that application.

I suspect something or someone has made this association with VLC. There is a way of breaking this connection, but it has temporarily moved to the archive section of my grey matter.

Someone else will probably provide some details.

On linux MATE which is a copy of winders look and feel, you simply right click the file and associate the correct application and tick the 'remember this choice' box

Video files. Until recently they displayed a thumbnail but now they display an icon (traffic cone). I just want to return to the thumbnail.

It does know as it displays the VLC media icon. The association appears to be in place already.

I did. I went to the default apps and selected VLC media. My question is why Windows Explorer has stopped displaying the thumbnails that it used to.

VLC sets up the association at install time by default.

'Open with' right click menu entry.

It is the overall manager of the activity, obviously. The blame is not far removed. But the thumbnails are created by "Providers" and if a filetype has no thumbnail, you need to find a provider software to do it. That's how PDF files get a thumbnail (Adobe software does it).

There's lots of stuff that does not work normally. Like, Windows Defender. All sorts of symptoms. Signs at startup it isn't running or hasn't started yet (which is rubbish, because it has to start as early as possible, if it expects to stop anything).

I have some problems here, that have defeated my repair abilities. A disk that used to be "quiet", now gets a lot of annoying "green bar" activity (some kind of scanning, just about every time you touch the thing). I tried re-paving the partition (take the files off, reformat, put files back on), but symptoms remain. I might have to wait 30 seconds for the green bar to stop, so I can see the filenames in File Explorer.

Paul

Good, thanks. I thought I had worked through all the options but your link has some new ones to try.