Overview

• Insider sleuth phantomofearth spotted the capability in recent Dev and Beta builds, including build 26220/26x20.6690.
• The feature can be enabled via feature ID 57645315 followed by an explorer.exe restart, after which videos appear as selectable backgrounds in Settings.
• Supported formats include .mp4, .m4v, .mkv, .mov, .wmv, .avi, and .webm, with playback triggered when the desktop is in view.
• Hands-on testing reports looped playback that continues with apps open and no meaningful increase in power use observed so far.
• Early implementation appears non-interactive and may restrict large or long files, and Microsoft has not announced availability or timing.