Windows 11 preview builds hit expiry time bomb, force restarts

Windows 10 and 11 preview builds have a built-in digital certificate that controls their expiry date, leading to a 'time bomb' scenario when they expire. Users running the Windows 11 Experimental Future Platforms must upgrade to the latest build (29634.1000) before August 11, 2026, when the current digital certificate expires. Once a build expires, users will face disruptive full-screen popups and scheduled restarts every four hours until they upgrade. To avoid these issues, it's vital to update regularly.