To manage thumbnail previews through File Explorer on Windows 11, use these steps:

• Open File Explorer.
• Click the "See more" menu and choose Options.

• Click the View tab.
• (Option 1) Check the "Always show icons, never thumbnails" option to turn off the feature.

• (Option 2) Clear the "Always show icons, never thumbnails" option to turn on the feature.
• Click the Apply button.
• Click the OK button.
• Once you complete the steps, the File Explorer settings will apply to turn thumbnails for files and folders on or off.