Microsoft will change Secure Boot certificates in June 2026, impacting Windows 11 PCs. If users do not update the certificates, their PCs may still function but will lack critical boot updates and malware blacklists, potentially compromising security. Without the new certificates, systems cannot run the latest Windows Boot Manager, making them vulnerable to bootkit malware and hindering future Windows feature updates. Older computers using BIOS are exempt from this issue. The new Secure Boot certificates are valid until 2038. Users can check their Secure Boot status in the Windows Security app; a green circle indicates readiness for the deadline.