KB5089416

Microsoft released cumulative update KB5089416 (Build 28020.2075) for Windows 11, version 26H1 for insiders on the Canary channel. The update contains a small set of general improvements and fixes that enhance the quality of experience for insiders with this build.

• Input improvement: enhanced typing reliability when using the ADLaM layout.
• Input improvement: enhanced performance of opening the clipboard history log.
• Font improvement: updated Leelawadee UI font family for Thai, Lao, Khmer, and Lontara script. Improved glyph sequence, positioning, and rendering.

Known issues: these builds may be unstable and released with limited documentation. The desktop watermark in the lower right corner is normal for Windows Insider preview builds. Some features under active development that Microsoft previews to insiders may not be fully localized. Localization will be completed as features are finalized. If you notice localization issues in your language, report them via the Feedback Hub app.

Installation is done through Windows Update: go to Settings > Windows Update and click Check for updates. A computer restart is required to complete the installation.

Notes for insiders on the Experimental channel (26H1): builds released to this channel represent the latest platform changes in early development stages and are not tied to any specific Windows release. Features and capabilities included in these builds may never ship in the final version, as Microsoft tries out different concepts and gathers feedback.

Features may change, be removed, or be replaced, and some may never become available outside the Windows Insider program. However, when these features are ready, they may appear in future Windows releases. Many features on the Experimental channel (26H1) are distributed using Controlled Feature Rollout technology. They initially become available to a small group of insiders, and then their availability expands as feedback is received and analyzed to assess how they are received before becoming available to all participants in this channel.

How the new features work:

Input improvement: enhanced typing reliability: Improved handling of key press sequences for the ADLaM layout. The system no longer drops keyboard events during fast typing by increasing the input buffer depth and optimizing the message queue in the win32k.sys window manager thread.

Input improvement: enhanced performance of opening the clipboard history log: Faster invocation of the clipboard history (Win+V) via deferred loading of format metadata and asynchronous deserialization of entries from %LocalAppData%\Microsoft\Windows\Clipboard*.dat. The UI appears immediately with placeholders; full data loads on scroll.

Font improvement: updated Leelawadee UI font family: The updated font correctly renders Thai, Lao, Khmer, and Lontara glyphs thanks to reworked GPOS (positioning) and GSUB (substitution) tables. Diacritic placement and kerning rules for complex syllables are improved.

The last 10 Windows updates: