What's new in KB5079489 (Windows 11 build 28000.1764)
- Windows 11, version 26H1
- OS Build 28000.1764
Maya Reyes4 min readQuick answer
KB5079489 is an optional non-security preview update for Windows 11 version 26H1 that increments your operating system version to OS Build 28000.1764. Released on March 26, 2026, it offers early access to quality improvements and system refinements ahead of the next mandatory update cycle. Users can install it manually through Windows Update or download the standalone package directly from the Microsoft Update Catalog.
Microsoft has released KB5079489 for devices running Windows 11 version 26H1, bringing the operating system build number up to OS Build 28000.1764. Published on March 26, 2026, this update arrives as an optional non-security preview update. It gives desktop users and IT administrators an advance look at upcoming system fixes and internal refinements before they are bundled into the mandatory cumulative security updates scheduled for the following month.
Because KB5079489 is an optional preview release, Windows 11 will not download or install it automatically unless you explicitly search for optional updates in your system settings or apply the standalone installer manually. The release specifically targets systems running Windows 11 version 26H1. Devices operating on other branches, such as Windows 11 version 24H2, version 25H2, or version 23H2, receive distinct servicing packages tailored specifically to their respective build trees.
Understanding where preview updates fit into Microsoft's monthly maintenance schedule helps you decide when to update. Near the end of each month, Microsoft publishes optional releases to test non-security quality fixes across broader production environments. For everyday desktop users, deciding whether to install OS Build 28000.1764 comes down to whether you are troubleshooting a specific issue that this build addresses or if you prefer to maintain maximum stability by sticking strictly to automated monthly security updates.
Highlights
- OS Build 28000.1764 serves as the primary preview update baseline for Windows 11 version 26H1, officially released on March 26, 2026.
- Update servicing directly advances the OS build structure from the previous update KB5079466 (OS Build 28000.1719), which was released on March 10, 2026.
- Establishes essential system refinements and platform updates that feed into subsequent cumulative updates, such as KB5083768 (OS Build 28000.1836) and KB5083806 (OS Build 28000.1896).
- Non-security preview status provides early validation across consumer and enterprise devices operating on Windows 11 version 26H1.
- Continuous update progression aligns version 26H1 builds with upcoming servicing milestones leading up to KB5127646 (OS Build 28000.3231).
Known issues
Microsoft reports no known issues for this update.
Should you install it?
Whether you should install KB5079489 depends on your individual maintenance workflow and operational requirements. Because this release is classified as an optional preview update, installation is completely voluntary. If your computer running Windows 11 version 26H1 is functioning smoothly without any technical glitches or performance issues, there is generally no urgent need to install preview software immediately. Most everyday users benefit from waiting until these quality changes are validated further and bundled into the mandatory monthly security patch.
However, if you are a system administrator testing software compatibility across your organization, or an enthusiast who prefers to evaluate platform updates as soon as they become available, downloading KB5079489 lets you review these fixes early. Should you choose to skip this optional preview, all of its underlying quality fixes will automatically be included in the mandatory update delivered during the next Windows Update servicing cycle.
Before proceeding with any operating system update, it is always advisable to back up critical files or create a system restore point. This ensures you can easily revert your device to a stable configuration should you encounter unexpected behavior after updating.
How to get it
Illustration: the Optional updates page under Windows Update > Advanced options
You can obtain KB5079489 (OS Build 28000.1764) directly through the built-in Windows Update tool or by downloading the standalone installer file from Microsoft's distribution catalog.
To install KB5079489 using Windows Update:
- Click the Start button and select the Settings icon.
- Choose Windows Update from the left-hand navigation bar.
- Turn on the switch for "Get the latest updates as soon as they're available" if you want preview releases offered to your device immediately.
- Select the Check for updates button.
- When KB5079489 appears under the optional updates section, click Download & install.
- Restart your computer when prompted to finish applying OS Build 28000.1764.
If you prefer to perform an offline installation or need to update multiple computers without downloading the files repeatedly, you can download the standalone file directly:
- Open your Web browser and visit the Microsoft Update Catalog site.
- In the search box, enter KB5079489 and press Enter.
- Identify the update package that matches your specific system hardware for Windows 11 version 26H1.
- Click the Download button next to the relevant package and open the provided link to save the installer file.
- Double-click the downloaded file to run the standalone update setup and follow the onscreen prompts.
If you encounter any difficulties during the download or installation phase, generic troubleshooting steps can help. Try running the automated Windows Update troubleshooter found under Settings > System > Troubleshoot > Other troubleshooters. You can also ensure your primary hard drive has adequate free storage space and verify that your internet connection remains stable throughout the download process.
Sources
Frequently asked questions
What is KB5079489?
KB5079489 is an optional preview update released on March 26, 2026, for Windows 11 version 26H1, bringing the operating system to OS Build 28000.1764.
Is KB5079489 required or mandatory?
No, KB5079489 is an optional preview update. Windows 11 will not install it automatically unless you manually select it in Windows Update or run the offline installer.
What build number does KB5079489 install?
Installing KB5079489 updates your Windows 11 version 26H1 system to OS Build 28000.1764.
What can I do if KB5079489 fails to install?
You can run the Windows Update troubleshooter in Settings, check that your computer has sufficient free disk space, or download and install the package manually from the Microsoft Update Catalog.
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Covers Windows 11 update releases and the problems that follow them. Tracks Microsoft's release-health notes daily and flags known issues the same day they appear.
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