Windows 10: In windows 10 v 20H2 don't have some thumbnail preview for some pictures

Firstly , when I went into my desktop , my windows defender settings were all off for all virus and threat protection settings for some reason . Then I went into a browser and searched how to fix the problem , I found many videos but when I selected one it said go to powershell and type "DISM.exe /Online /Cleanup-image /Restorehealth" , but it got stuck at 55.5%

and not knowing the results , I closed powershell admin and now I don't have thumbnail preview for some pictures . And when I clicked on one image, it shows a property panel. I currently don't know how to fix this problem . please help me

:)

 

Windows 7 wrong thumbnail picture

Either, what Mussels said, or...
Looks like you have dis-abled thumbnail previews some how... as, that is the default file folder icon.

If you are using any system speed up utilities, they may have disabled it.
Look here and try to turn it back on.
How to Enable or Disable Thumbnail Previews in Windows 7 Explorer

 

Video preview thumbnails

Hello,

System file corruption is one of the possible reasons why thumbnail preview has recently disappeared. To better assist you, please answer the following:

• For clarification, are referring to video preview thumbnails when using File Explorer?
  
• We would like to verify if you are referring to the Fall Creators Update. To see your
  Windows build and version, please follow the steps in this
  article.
  

In the meantime, we suggest creating a Test User Profile. This is to see if the same issue occurs on a different user profile.

To create a Test User Profile, follow these steps:

• On Search, type Settings then hit the
  Enter key.
• On Settings window, select Accounts.
• Select Family & other people.
  
• Select Add someone else to this PC.
• Name the User Profile as TEST.
• Assign a password for TEST user, then select Next.
• Sign in TEST user.

We'll be waiting on the results.

 

Getting rid of taskbar thumbnail previews in windows 10

I want to remove the preview also then I used Taskbar Thumbnails Tuner to achieved it. Although it said it is working on Windows 7 and 8 only, I have tested it is also working on Windows 10. The step is simple:

1. Click "Disable Thumbnails"
   
2. Click "Apply"
   

No need to restart or logout to take effect