KB5102945

Microsoft has released cumulative update KB5102945 (Build 28120.2315) for Windows 11, version 26H1 for insiders on the Experimental channel.

• Accessibility. Improved responsiveness of the subtitle style — subtitles are now redrawn immediately when their style is changed. If subtitles are not currently displayed, a sample subtitle text is shown.
• Audio. Improved reliability of the built-in HD Audio driver.

Builds released to the Experimental channel (26H1) represent the latest platform changes at early stages of development 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 replaced, and some of them 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 rolled out using Controlled Feature Rollout technology. They first become available to a small group of insiders, and then their availability expands as feedback is received and analyzed to assess how they are perceived before becoming available to all participants on this channel.

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

To update Windows 11, version 26H1 (Experimental) to build 28120.2315, you can also download update KB5102945 and install it manually using the links above.

How the new features work:

Accessibility. Instant Subtitle Style Rendering. The mechanism intercepts the property change event in the CaptionStyle object and immediately triggers a forced invalidation of the drawing area via an InvalidateRect call. If the rendering queue is empty and subtitles are inactive, the UI thread extracts a localized template preview text from the assembly resources and passes it through the DirectWrite pipeline to display the sample, ensuring immediate feedback.

Audio. Enhanced Reliability of the Built-in HD Audio Driver. The power management subsystem of the HDAudBus functional driver, responsible for interfacing with the codec via the DMA channel, has been refactored. The handling of D3/Hot transitional power decay states, where earlier driver versions could misinterpret the WAKE_EN root line status, has been strengthened. The codec re-initialization algorithm upon resume from sleep has been refined to eliminate audio stream hang-ups caused by desynchronization of the stream ring buffer cyclic position counter.

The last 10 Windows updates: