Microsoft Releases Windows 11 KB5077241 Preview Update with BitLocker Improvements and Built-In Sysmon

Microsoft has released the KB5077241 optional update for Windows 11, bringing a batch of performance enhancements, usability improvements, and new tools for administrators and IT professionals. This preview update is part of Microsoft’s monthly non-security quality releases, which allow users to test upcoming changes ahead of the regular Patch Tuesday cycle.

What’s New in KB5077241

The update introduces a variety of enhancements designed to improve both the experience and security of Windows 11 systems:

Improved BitLocker ReliabilityOne of the key updates addresses reliability issues with BitLocker encryption. After this update, Windows devices should no longer freeze when a recovery key is entered at startup, fixing a frustrating edge-case for encrypted systems.

Built-In System Monitor (Sysmon)Perhaps the most significant addition is native support for System Monitor (Sysmon) — a powerful event logging and system monitoring tool commonly used by security teams. While Sysmon has previously been available as part of the Sysinternals suite, this update brings it directly into Windows 11 as an optional feature administrators can enable. It provides detailed logging of process events, network connections, and more, feeding information into the Windows Event Log for use by security tools and monitoring solutions.

New Network Speed Test ToolWindows 11 now includes a built-in network speed test accessible right from the taskbar. Users can test Ethernet, Wi-Fi, or cellular connections by accessing Quick Settings or right-clicking the network icon, which opens the speed test in a browser window.

Other Quality Fixes and FeaturesThe update also includes a range of smaller but useful enhancements:

• File Explorer improvements such as reliably opening new windows and better handling of archives.

• Support for setting WebP images as desktop backgrounds without needing conversion.

• Better taskbar behavior when multiple windows are open.

• Reliability and performance fixes for sleep/resume, printing, and user interface elements.

Finally, the update also rolls out updated Secure Boot certificates to eligible devices as part of Microsoft’s efforts to maintain secure boot chains as older certificates near expiration later this year.

How to Install

As a preview update, KB5077241 won’t install automatically unless a user chooses to install it. To get it, open Settings > Windows Update and click Check for updates, then follow the prompts to download and install the update. It can also be installed manually via the Microsoft Update Catalog for those who prefer direct installation.