來源：https://answers.microsoft.com/en-us/windows/forum/all/always-show-icons-never-thumbnails-option-not/31a04351-eaf7-4ed0-9b1f-d74682514f11

順利解決縮略圖不顯示的問題。有可能會問是否替換，輸入yes即可。

Based from the screenshot that you've provided, it appears that the option to enable or disable Always show icons, never thumbnails has been missing which can be caused by an application that changes the value on the Registry or corruption of the system file that is handling the File Explorer Options. This can be resolved by adding the option on the Registry using the Command Prompt. To do this, follow the steps below: 

1. Click Start and type cmd in the search box. Right-click and select Run as administrator.
2. Copy and paste the command below into the Command Prompt window and press Enter:

   REG ADD HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer /v DisableThumbnails /t REG_DWORD /d 0
   Note: After pressing Enter, you will receive a message saying The operation completed successfully

3. Once it's successful, close the Command Prompt window.
4. Restart your computer for the changes to take effect and check if the issue persists.