Microsoft releases Windows 11 Insider Preview Build 26220.9606

Microsoft has released Windows 11 Insider Preview Build 26220.9606 to the Beta Channel. The build, dated October 7, 2026, gives the lock screen a more focused default widget setup and fixes a crash affecting some apps and games.

Weather leads the lock screen

Microsoft is changing the default lock screen widget experience for Insiders on newer builds. Weather becomes the primary widget shown on the lock screen, and the amount of recommended widget content is reduced. The company says the change is part of its commitment to making Windows calmer and higher quality, with the aim of a more focused experience.

Users also get more control over what appears. Microsoft says people can curate the widgets they find most useful for them. The settings live under Settings > Personalization > Lock screen. As with all Insider builds, Microsoft notes that features may change, be removed, or never get released beyond Windows Insiders.

Fix for msmpeg2ac3dec.dll crashes

The build also includes a fix for an issue with msmpeg2ac3dec.dll that was leading to some apps and games crashing recently. The release notes do not describe the cause or name any affected software.

Separately, Microsoft documents a confirmed known issue on its release health page. After the September 22, 2026 update (KB5124010) and later updates, some applications that require AC-3 (Dolby Digital) audio decoding might close unexpectedly. It affects Windows 11 versions 24H2, 25H2, and 26H2. Microsoft says it is more likely to hit legacy applications that rely on Windows built-in audio decoding, while many modern apps ship their own decoders and are unlikely to be affected. The timing and symptoms look related to the Beta fix, although Microsoft has not said the two are the same problem. The company says it is working on a resolution for a future Windows update.

Availability

Build 26220.9606 is based on Windows 11, version 25H2, and is delivered through an enablement package. Microsoft’s note does not say when the beta fix will reach the public release, so anyone hit by the crashes outside the Insider program still has to wait. Insiders can check Flight Hub for a full look at which build sits in which channel.