Windows 11 build 25905 outs in the Canary Channel

A new preview build in the Canary Channel is releasing for Windows 11, and here's what you need to know.

Windows 11 update settings
Windows 11 update settings
  • Microsoft is rolling out a new preview of Windows 11 (build 25905) in the Canary Channel.
  • This flight introduces Rust in the kernel, removes ARM32 support, and adds a new authentication policy.
  • The update also ships with various changes and improvements. 

Microsoft is rolling out Windows 11 build 25905 for computers enrolled in the Canary Channel of the Windows Insider Program, and it includes some new changes and improvements.

Build 25905 for Windows 11, according to the official changes, ships with early implementation of critical kernel features in safe Rust, removes support for ARM32 Universal Windows Platform applications (UWP), and includes a new Post Authentication Actions policy.

In addition, build 25905 introduces a new color format for richer emoji with a 3D-like appearance, and the Microsoft Store gets also updated with a new section that promotes AI applications.

Windows 11 build 25905

Here are all the new features and improvements for the latest release of Windows 11 in the Canary Channel:

Rust for Windows Kernel

As previously spotted, starting on build 25905, Windows 11 introduces an early implementation of Rust for critical kernel features. Rust is an open-source programing language designed primarily to build operating systems, but it also works to build applications. This language is very popular among programmers since it offers syntax and performance similar to C++ and provides greater memory security without garbage collection.

In this first preview, the company is adding Rust for a small set of features, including “win32kbase_rs.sys” which contains a new implementation of GDI region. 

ARM32 app support

Microsoft is also removing support for ARM32 UWP applications from ARM-based devices, which that after this update, ARM32 apps will no longer launch on your computer. (ARM64 apps are not affected by this change.)

If you still use ARM32 apps, you will need to uninstall them manually and then reinstall them again from the Microsoft Store.

Post Authentication Actions

As part of the new Windows Local Administrator Password Solution feature, this flight also updates the “PostAuthenticationActions” policy to include an option called “Reset the password, logoff the managed account, and terminate any remaining processes” to terminate specific individual processes that are launched in an OTS (over-the-shoulder) elevation scenario, for example, using “runas.exe.”

Emoji new font color 

The development team is also rolling out a new color font format to COLRv1 to display richer emoji with a 3D-like appearance.

Emoji new font color
Emoji new font color / Image: Microsoft

Microsoft Store new AI hub

Finally, the Microsoft Store app is getting an update that brings a new AI Hub that promotes the best AI experiences built by the developer community and Microsoft.

As part of the known issues, this build will not be offered to ASUS devices or PCs with ASUS motherboards, and the Ethernet-connected devices may lose network connectivity after updating to this build. 

Installing builds

To download and install the Windows 11 build 25905, you must enroll your device in the Canary Channel through the “Windows Insider Program” settings from the “Update & Security” section. Once you enroll the computer in the program, you can download the build from the “Windows Update” settings by clicking the “Check for Updates” button.

About the author

Mauro Huculak is a Windows How-To Expert who started Pureinfotech in 2010 as an independent online publication. He has also been a Windows Central contributor for nearly a decade. Mauro has over 14 years of experience writing comprehensive guides and creating professional videos about Windows and software, including Android and Linux. Before becoming a technology writer, he was an IT administrator for seven years. In total, Mauro has over 20 years of combined experience in technology. Throughout his career, he achieved different professional certifications from Microsoft (MSCA), Cisco (CCNP), VMware (VCP), and CompTIA (A+ and Network+), and he has been recognized as a Microsoft MVP for many years. You can follow him on X (Twitter), YouTube, LinkedIn and Email him at [email protected].