If you would like Windows to recognize all the extra video formats that don’t show a thumbnail preview image, the operating system has to be helped to identify what the format is. If the format is not supported your thumbnail will be a standard icon for that file type or a blank icon. Windows 10 can show Matroska (MKV) thumbnails as standard and has better MP4 support although there are still several video formats that no version of Windows supports out of the box. Support for displaying video thumbnails has increased with each new Windows release as new video formats become integrated by default. A video thumbnail will be a still frame taken at random from near the start of the video. When certain images and video files are viewed as icons, instead of a generic file type icon you will see a thumbnail preview image from the content of the file. They can effectively be viewed as lists, detailed lists, tiles or different size icons. Anybody that uses Windows File Explorer will know there’s a few different modes to display files.
