Microsoft is continuing the rollout of Secure Boot certificate updates, with the next significant deadline on October 19, 2026, when the Microsoft Windows Production PCA 2011 certificate expires. The September 2026 Patch Tuesday update has expanded eligibility for Secure Boot certificates to more PCs classified as “high confidence.” Users may need to reboot their PCs to install these updates, and some may require firmware updates beforehand. Microsoft has confirmed that the update process will persist beyond established deadlines, and older certificates are expiring in stages, with the first two deadlines having already passed. Users should ensure they have the latest updates installed and check their Secure Boot status in Windows Security. Microsoft has assured that PCs without the newer certificates will continue to boot normally and receive standard updates while the rollout continues.