Windows PCs are experiencing multiple reboots during the installation of monthly cumulative updates, particularly due to updates related to Secure Boot certificates and accompanying firmware updates. Microsoft is rolling out the Secure Boot certificate update to millions of Windows 11 and Windows 10 devices, with users who haven't received the certificates expected to do so soon, unless firmware limitations arise. Microsoft has acknowledged that multiple reboots may occur during this rollout. The August 2026 Patch Tuesday update addressed around 400 security vulnerabilities and included a Secure Boot certificate update for a wider range of devices. It is advised not to delay updates beyond three days to avoid potential AI-driven security threats. The August 2026 Update also activates the Low Latency Profile for app launches and improves file size displays in File Explorer. Reports indicate that devices lacking the Secure Boot 2023 certificate have successfully received it following this update, and Microsoft will continue deploying certificates via Windows updates in the coming months.