Microsoft has expanded the rollout of the Secure Boot 2023 certificate update to more Windows 11 and Windows 10 devices with the June 2026 Patch Tuesday update (KB5094126). This update aims to ensure that most supported consumer PCs are classified as high confidence, meaning necessary certificates are either installed or will be applied automatically. Secure Boot is a firmware security feature that verifies the software attempting to load during the startup process, blocking unauthorized software. The certificates supporting Secure Boot, issued in 2011, are expiring in stages starting June 24, 2026, prompting Microsoft to deploy replacement certificates. Most home users do not need to take manual action as the updates will occur automatically via Windows Update. Users can check their Secure Boot certificate status in the Windows Security app. A yellow warning indicates pending compatibility data, while a red alert suggests a firmware incompatibility requiring a BIOS update. Multiple reboots during the update process are normal, and a new SecureBoot folder in Windows is for staging cryptographic files. Older PCs may experience longer update times, and some may not receive updates due to firmware issues. HP users should check for BIOS updates if encountering BitLocker recovery loops. IT administrators should monitor device classifications and manually initiate updates for devices not in the high confidence category. Devices with Secure Boot disabled cannot receive updates, leaving them vulnerable. The expiration of the Microsoft Corporation KEK CA 2011 certificate on June 24 does not immediately affect device functionality, but it limits Microsoft's ability to sign new bootkit blacklist updates.