Build 27774: Windows Insider Experimental Channel, January 2025. Partition formatting confirmation and Administrator protection settings

Adds confirmation when you format or delete partitions and lets you enable Administrator protection in Windows Security.

Does it affect you? Applies to: Devices enrolled in the Windows Insider Program’s Experimental Channel.

Review notes Additional details from the official release notes (2) Read notes

This page Build 27774 was released to the Canary Channel.
In detail On a new Copilot+ PC joining Canary from Dev, Release Preview, or retail, Windows Hello PIN and biometrics are lost with error 0xd0000225. The PIN should be recreatable by clicking “Set up my PIN.”

The official sources are linked at the end of the page.

This is a test build for people in the Windows Insider Program. Features in it can change, be removed, or never reach regular Windows releases.

What changes

For: Insiders in the Experimental Channel

Accent-colored window borders and window shadows appear when enabled, and window animations stay off when their setting is turned off.¹

For: Xbox app users in the Experimental Channel

The Xbox app no longer sometimes fails to launch with a “Please try again” error.²

For: People installing Windows from installation media

Windows Setup shows a confirmation dialog when you format or delete partitions during installation.³

You can enable Administrator protection in Windows Security under Account Protection without help from IT. Windows home users can enable it there too, and changing the setting requires a reboot.⁴

With Administrator protection enabled, the authorization prompt for untrusted and unsigned apps has larger color-coded areas extending over the app description.⁵

Data sheet · Security · Downloads · Components Click to collapse or expand

Version	Build	Channel
—	27774	Experimental Channel

No vulnerabilities are listed for this update.

Updated Oct 27, 2026

Cited passages from Microsoft's official notes (5)

1. Fixed an underlying issue causing accent colored window borders to not be not displayed when enabled, shadows around windows not displaying when enabled, and window launching (and other) animations to show even though the setting to show animations is turned off in the latest Canary builds. blogs.windows.com
2. Fixed an underlying issue which was causing the Xbox app to fail to launch with a “Please try again” error sometimes in the last two Canary builds. blogs.windows.com
3. When installing Windows from installation media, you will now see a confirmation dialog when formatting or deleting partitions. blogs.windows.com
4. Administrator protection can now be enabled from Windows Security settings under the Account Protection tab. blogs.windows.com
5. With administrator protection enabled, the prompt requesting the user’s authorization for elevating untrusted and unsigned applications now comes with expanded color-coded regions which will now extend down over the app description. blogs.windows.com

Checked automatically: 8 of 8 checks passed, 5 quoted passages

A second AI read the text against the sources: correctness 3/5, clarity 4/5, completeness 4/5. How we work

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