Desktop background black

The background is being saved for the current session but not surviving a restart, so the recent update, theme synchronization, or a policy may be resetting personalization. Open Settings > Personalization > Background, choose Picture, select a local image, and confirm it remains after signing out and back in. Temporarily disable Windows theme synchronization under Accounts > Windows backup and test again. Verify the image still exists and is not in a temporary or disconnected OneDrive location. If this is a managed PC, run gpresult /h report.html and ask the administrator whether a desktop-wallpaper policy applies. Create a new local user and repeat the test; persistence there would isolate the original profile. Since the issue followed specific updates, review their known issues and submit the reproduction through Feedback Hub. Uninstall an update only after the profile and policy checks fail to explain the reset, and create a restore point first.