Microsoft has started rolling out the June 2026 Patch Tuesday update for Windows 11, and this release is much bigger than a routine monthly security patch. The update, listed as KB5094126, applies to Windows 11 versions 25H2 and 24H2. Depending on your version, it moves the system to OS Build 26200.8655 or 26100.8655. More importantly, it brings one of the most packed Windows 11 monthly updates in recent memory.

Microsoft has issued an important warning for Windows users, and this one is not just about another routine monthly update. The company has confirmed that Secure Boot certificate expiration, which begins in June, will affect most Windows devices. Because of that, Microsoft is asking users and organisations to make sure their systems receive the latest updates before the deadline to avoid possible boot or security-related issues.

Secure Boot has been around since 2011, quietly doing one very important job: stopping unauthorized or tampered code from sneaking into your PC during the boot process. It's also one of the reasons Windows 11 has stricter hardware requirements — Microsoft wants more devices to have this boot-level protection turned on and working properly.

If you're seeing "2026-02 Security Update (KB5077181) (26200.7840)" with a restart prompt, that's the February 2026 mandatory cumulative security update for Windows 11 version 25H2 (build 26200.7840). The same update also applies to Windows 11 24H2 (build 26100.7840), but your screenshot is clearly the 25H2 build line.

That "2026-01 Preview Update (KB5074105) (26200.7705)" you're seeing isn't a typical Patch Tuesday security drop. It's a non-security preview update for Windows 11 (listed for version 25H2 and 24H2) that focuses on new features plus a long list of reliability fixes.