KB5079466 (build 28000.1719) for Windows 11 26H1 drops as the March 2026 update

Windows 11 build 28000.1719 (KB5079466) arrives as the second cumulative update version 26H1.
This release includes fixes, improvements, and changes for specific computers.
Windows 11 26H1 will be exclusively availble on new devices with specific processors, and not for existing PCs.

Microsoft has made available the Windows 11 build 28000.1719 (KB5079466) as the March 2026 update for devices running version 26H1.

According to the changelog, the “2026-03 Security Update (KB5079466) (28000.1719)” includes only several fixes and improvements related to Secure Boot, Windows Defender Application Control, and Windows System Image Manager.

It’s worth noting that Windows 11 26H1 is not a version for current devices. Microsoft has explicitly stated that version 26H1 is not an upgrade path for Windows 11 25H2 or earlier releases.

According to the company’s newly published Microsoft Health Dashboard page, version 26H1 is a hardware-optimized release designed to enable next-generation silicon developed in partnership with device manufacturers and silicon partners. This release will be available exclusively as a preinstalled experience on select new devices beginning in early 2026, with capabilities tailored specifically for those platforms.

Microsoft is referring to the new ARM64 PCs, starting with devices powered by the Snapdragon X2 Plus, Elite, and Extreme processors. If you own a computer running on Intel or AMD hardware, Windows 11 26H1 will never be offered to your system.

What’s new on Windows 11 25H2 and 24H2 update KB5079466
Windows 11 March 2026 Patch Tuesday – Manual installation process
Windows 11 March 2026 Patch Tuesday – Update history

Important: Usually, Microsoft doesn’t release new features immediately. When a feature is announced as part of an update, it usually signals the start of a gradual rollout using the Controlled Feature Rollout (CFR) technology. Availability can vary based on region, hardware, and software configuration. For instance, some features take longer to reach users in Europe due to regulatory requirements.

What’s new on Windows 11 26H1 update KB5079466

Microsoft is currently rolling out these improvements and fixes as part of the March 2026 Security Update for Windows 11 26H1.

Windows System Image Manager: Improves the reliability of selecting trusted catalog files by adding a warning dialog that helps confirm the chosen file comes from a trusted source.
Windows Defender Application Control: Improves how WDAC handles COM object allowlisting policies. Previously, COM objects were blocked when the endpoint security policy was set higher than the allowlisting policy, and with this update, COM objects are allowed as expected.

Finally, this update continues the rollout of the 2023 Secure Boot certificates for devices with the 2011 certificates expiring in June 2026. You can also apply the Secure Boot certificates manually with these instructions.

Windows 11 March 2026 Patch Tuesday – Manual installation process

Since there’s always a chance of problems during and after applying a quality update, it’s recommended to prepare your computer by creating a restore point and a full backup before proceeding with the installation.

To download and install this Windows 11 update, open the “Windows Update” settings and click the “Check for Updates” button.

If your computer has issues after installing this package, follow these instructions to uninstall the March 2026 update. If you’re unable to uninstall the update, follow these steps to recover your device.

The update will download and install automatically. However, you can also apply it manually by downloading the update KB5079466 from the Update Catalog website.

Windows 11 March 2026 Patch Tuesday – Update history

Final Release – Patch Tuesday (Stable Channel):
- Windows 11 26H1 build 28000.1719 release date: March 10, 2026. Official notes.