build expiration

Build expiration refers to the time-limited lifespan of Windows Insider Preview builds. Microsoft issues expiration notifications and eventually forces reboots or prevents booting on outdated builds. For example, builds older than September 15th began showing daily expiration warnings, followed by reboots every three hours from October 1st, and finally stopped booting entirely by October 15th. To avoid disruption, users must update to a newer build via Windows Update. This process ensures Insiders stay on supported, secure versions and helps Microsoft manage testing cycles. The tag covers official announcements and reminders about build expiration policies for Windows 10 Insider Preview builds.