The Performance Hit
By default, when you open a folder containing images, videos, or PDFs in Windows 11 File Explorer, the operating system works in the background to read each file and generate a tiny preview image (a thumbnail). While visually helpful for finding a specific family photo, this feature can severely cripple system performance. If you open a folder containing thousands of high-resolution RAW photos or massive 4K video files, File Explorer will freeze and consume massive amounts of CPU and disk I/O as it struggles to render thousands of thumbnails simultaneously.
Switching to Icons
To drastically improve folder loading times and stop Windows 11 from automatically generating thumbnails, you must force File Explorer to display generic file type icons instead.
Open File Explorer (Windows Key + E). Click the three horizontal dots (…) on the far right side of the top command bar. From the drop-down menu, select Options. A “Folder Options” dialogue box will appear. Click on the View tab at the top. In the “Advanced settings” scroll box, look at the very first option in the “Files and Folders” section. It is a checkbox labelled Always show icons, never thumbnails. Check this box. Click Apply, then click OK. Instantly, all image and video previews will disappear, replaced by the generic icon for your default photo viewer or media player, and massive folders will now load instantly.