Microsoft is concluding the week by releasing two new builds of Windows 11 for testers in the Dev and Beta Channels. Dev Channel build 23526 enhances the rich thumbnail preview in the Start Menu and the Cast flyout in Quick Settings, while Beta Channel build 22631.2199 introduces native support for additional archive file formats and other features that will be included in the upcoming Windows 11 version 23H2.

In the Windows 11 Dev Build 23526, Microsoft mistakenly released this build before quickly removing it from their servers. However, it is now available for all Dev Channel testers. The key changes in this build include:

1. New Build expiration date: All builds released on the Dev Channel will display a new expiration date of September 15, 2024, which has also been implemented in the Canary channel.

2. Rich thumbnail preview in Start Menu: For files that previously lacked rich thumbnail previews in the Start menu, Windows 11 now shows an updated tooltip instead of a blank preview area.

3. Updated Cast flyout: The Cast flyout in Quick Settings has been redesigned and now includes a link for users to seek support when encountering issues with discovering nearby displays, fixing connections, and more.

4. Never combined taskbar mode: By default, the setting for uncombining taskbar buttons on other screens has been disabled when no secondary monitors are connected.

In the Windows 11 Beta Build 22631.2199, Microsoft released two different builds on this channel. Build 22631.2199 incorporates new 23H2 features, while build 22621.2199 has these features disabled by default. The main new features are as follows:

1. Native support for .rar files: Windows 11 now supports additional archive file formats, including .rar, .tar, .tgs, .7z, and more.

2. Rich thumbnail preview in Start Menu: Same as mentioned above.

3. Never combined taskbar mode: Additional settings have been added for the never combine mode for the taskbar, including a new option to enable this mode for other taskbars in a multiple monitor scenario.

4. Snipping Tool update: The Snipping Tool app now includes new buttons to edit screenshots in Paint and edit screen recordings in Clipchamp.

5. App defaults: Apps now have the ability to direct users to the appropriate location in Settings to configure the default app for opening specific file types.

These are the main changes in the latest Insider builds. While the Beta Channel continues to receive new 23H2 features, Microsoft has also announced a special event on September 21, where they are likely to unveil new Surface devices and potentially provide a release date for Windows 11 version 23H2.