Windows 11 Update KB5077241: Native Sysmon, Speed Tests, and the 2026 Secure Boot Patch

Wednesday, February 25, 2026

Windows 11 Update KB5077241: Native Sysmon, Speed Tests, and the 2026 Secure Boot Patch

Released on February 24, 2026, Windows 11 KB5077241 (Builds 26200.7922 and 26100.7922) is an essential optional preview update for versions 24H2 and 25H2. While many previous updates focused on AI, this "C-release" delivers practical system tools and a critical security foundation for the upcoming Secure Boot certificate expiration.

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1. Integrated Network Speed Test

Microsoft has added a "Perform Speed Test" shortcut directly into the Windows Shell. This allows users to quickly verify their ISP performance without manual navigation.

  • Where to find it: Right-click the network icon in the System Tray or open the Wi-Fi/Cellular Quick Settings flyout.
  • How it works: It opens your default browser to a dedicated Bing/Ookla interface. It measures download, upload, and latency across Ethernet, Wi-Fi, and Cellular connections.

2. Native Sysmon Integration (Power User Feature)

The most significant addition for security enthusiasts is the native integration of System Monitor (Sysmon). Formerly part of the Sysinternals suite, it is now an optional OS feature that logs advanced system activity to the Event Viewer.

How to Enable Native Sysmon:
1. Open PowerShell (Admin).
2. Run: Dism /Online /Enable-Feature /FeatureName:Sysmon
3. Run: sysmon -i
Note: You must uninstall any standalone Sysinternals version first to avoid system hangs.

3. The June 2026 Secure Boot Crisis

This update includes critical targeting data for the Secure Boot certificate refresh. The original certificates issued in 2011 are set to expire on June 25, 2026. KB5077241 begins the phased rollout of the 2023 KEK and DB certificates. Without this patch (or the upcoming March 10 mandatory version), systems may eventually fail to boot or lose the ability to receive future security updates.

4. Key Performance Fixes

  • BitLocker Reliability: Resolves a bug where devices became unresponsive after entering the 48-digit recovery key.
  • Resume-from-Sleep: Significantly improves wake times for docked laptops and systems under high CPU load.
  • Taskbar Overflow: When set to "uncombined," the taskbar now only moves individual windows to the overflow menu instead of the entire app set, preventing UI clutter.
  • WebP Wallpapers: Native support for .webp files is now live in Settings > Personalization.

How to Install

Navigate to Settings > Windows Update and click "Check for updates." Look for the 2026-02 Cumulative Update Preview (KB5077241). If you miss this window, these features will arrive automatically on March 10, 2026 (Patch Tuesday).