Windows 11 Canary Build 27975: PIN Fix and Stability Tweaks

Microsoft has quietly shipped Windows 11 Insider Preview Build 27975 to the Canary Channel, and while this flight doesn’t add big new features, it delivers a series of stability and usability fixes — most notably a repair for a Windows Hello PIN regression that left some Insiders unable to sign in after upgrading unless they reset their PIN.

Background / Overview​

Canary-channel releases function as Microsoft’s test bed for early platform work: small, iterative updates that can contain both polish and experimental changes. Build 27975 continues that pattern — a largely maintenance-focused flight aimed at smoothing the update path for Insiders while addressing several annoyances reported over the last few weeks. The build targets input reliability, the Settings experience, and a thorny Windows Hello regression affecting PIN sign-in for some devices. The build notes surfaced in Insider channels and community mirrors, and echo earlier Canary fixes and known issues called out in adjacent flights.
This article walks through the concrete fixes in Build 27975, explains why the Windows Hello PIN problem mattered, assesses risks for Insiders and IT pros, and places the flight in the context of Microsoft’s broader 24H2/25H2 wave of refinements such as the redesigned Start menu, improved dictation, and Click-to-Do AI features that Microsoft has been rolling out through preview channels.

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What’s fixed in Build 27975​

Microsoft’s release notes and community posts for Build 27975 list a short set of targeted fixes. The headline items are focused and practical rather than feature-rich:

• Touch keyboard launch reliability — a fix to reduce intermittent failures when the touch keyboard is invoked on tablets and convertibles. This addresses an irritation that sometimes left users unable to summon the on‑screen keyboard when the device expected touch input.
• Windows Hello PIN sign-in — a repair for an issue where certain devices could no longer use their previously configured Windows Hello PIN after upgrading to recent Canary builds; recovery required resetting the PIN. The build restores continuity so that PIN sign-ins that had been broken post-upgrade once again work as expected on affected devices.
• Settings crash when viewing drive information — fixes a crash observed when navigating to Settings > System > Storage > (drive details). The same underlying bug could also cause File Explorer’s drive Properties page to fail when opening the drive details dialog. This should make routine storage troubleshooting more reliable.

These are modest but meaningful fixes for day‑to‑day reliability. Combined, they reflect Microsoft’s current emphasis on tightening basic platform behaviors ahead of broader rollouts.

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The Windows Hello PIN fix — what happened and why it mattered​

Windows Hello’s PIN feature is a device‑bound authentication mechanism that stores a locally protected credential, typically sealed with the platform’s Trusted Platform Module (TPM). When Windows reports “your PIN isn't available” or forces a reset after an upgrade, the problem can stem from:

• corrupted or inaccessible credential blobs (NGC data) stored under the system’s local service profile;
• a disruption in the TPM or its interaction with the OS’s credential manager; or
• changes in the update path that invalidate how encrypted PIN data is referenced after an upgrade.

In multiple Canary flights earlier in the year Microsoft has explicitly referenced PIN and Windows Hello setup failures in scenarios such as Entra‑joined devices and after certain system resets. Build 27975 targets one of these upgrade-related failures by repairing the code path that caused the PIN to become unusable and removing the need for a manual PIN reset in the impacted scenarios. The problem was widely reported by Insiders and within enterprise test groups because a broken PIN flow can block users from authenticating quickly and reliably.
Why this matters beyond convenience:

• Security expectations: Organizations and users adopting device-bound credentials expect a smooth upgrade path; interruptions to Windows Hello can force fallback to passwords or other less convenient flows, increasing friction.
• Operational impact: If employees in a test ring or pilot group lose PIN access after an update, help desk load rises and trust in preview servicing falls.
• Telemetry sensitivity: These PIN problems often appear only on specific hardware or when certain security features (for example, System Guard Secure Launch or DRTM) are enabled, so they can be difficult for developers and QA to reproduce at scale.

Microsoft’s fix in 27975 restores the expected behavior on affected devices, but the underlying environment (TPM, enterprise enrollment, and device configuration) remains a variable for further regressions, so cautious testing is still warranted.

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Technical dive: common recovery steps for PIN problems (practical guidance)​

For Insiders and IT administrators who encounter Windows Hello PIN issues, the following steps are the usual, practical recovery path. These steps are baseline — Microsoft’s fix in Build 27975 should reduce the need for them, but they remain useful when troubleshooting other PIN problems.

• Try simple fallback sign-in: use the Microsoft account or local password from the sign-in options. This is the fastest recovery to regain desktop access.
• Use “I forgot my PIN / Reset PIN” flow at the lock screen after authenticating with your password. Windows will re‑provision the PIN credential in many cases.
• If you can sign in with another administrator account, remove the corrupted NGC store and re-create the PIN:
• Delete C:\Windows\ServiceProfiles\LocalService\AppData\Local\Microsoft\NGC (requires administrator rights).
• Reboot and set up a new PIN under Settings > Accounts > Sign‑in options.
• If TPM or hardware security is implicated, update firmware and drivers, and consult your device vendor guidance. In enterprise environments with managed TPM ownership, coordinate with security teams before wiping or reinitializing TPM data.

These are known, field‑tested steps used by support teams. They’re effective for many causes of PIN failures but are not a replacement for Microsoft’s own remediation when an OS regression is the root cause. Use them with caution and after preserving relevant logs for Microsoft Feedback Hub if the issue is an Insider regression.

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Known issues in Build 27975 — why Canary still requires caution​

Even as Microsoft patches specific regressions in 27975, the Canary Channel continues to carry some higher‑impact known issues. Two items are worth highlighting for Insiders and admins:

• Start menu unexpected scrolling — Insiders using the new Start menu design may see it scroll to the top unexpectedly. This is a UI/UX annoyance that affects navigation and discoverability in the app list. Microsoft has flagged it as a minor known issue in the build notes.
• Power state regressions (sleep/shutdown) — Microsoft continues to investigate reports that sleep and shutdown may not work correctly on some devices after recent Canary updates. Because sleep and shutdown touch firmware, kernel power management, and drivers, this class of regression can be disruptive and has potential to cause data loss if unsaved work is lost when shutdown flows fail. Microsoft marked this as an active investigation item in adjacent Canary release notes and the issue has persisted across multiple builds for a subset of testers. This is a major reason Canary is unsuitable for production devices.

Practical rule: don’t run Canary builds on systems you can’t afford to have lose sleep/shutdown behavior, or on systems that must remain stable for daily business.

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Context: where Build 27975 sits in the 24H2/25H2 update stream​

Build 27975 is a small, maintenance-oriented Canary flight, and it arrives against a backdrop of larger changes Microsoft has been rolling through preview channels over the past months:

• Start menu redesign and UX experiments have been visible in Canary and Release Preview testing, with Microsoft iterating on a scrollable Start and category views intended to surface apps more efficiently. Some elements of the new Start menu have been promoted through the Beta/Release Preview channels but remain staged and controlled.
• AI and productivity features such as Click to Do, AI actions in File Explorer, and richer Windows Share experiences have been delivered incrementally via Insider previews, especially on Copilot+ hardware where on‑device AI acceleration is available. These larger changes are being shepherded in parallel to the smaller stability flights like 27975.
• 24H2 and 25H2 servicing model: Microsoft’s 25H2 update has been delivered as an enablement package in many cases and is designed to be lightweight, with many feature refinements arriving through monthly updates and Insider previews rather than a monolithic release. That approach means Canary builds are where many early UI and interaction experiments appear first; fixes like those in 27975 are part of keeping the test pool healthy.

Cross-referencing the trajectory of previous Canary flights makes clear that Microsoft is balancing two simultaneous priorities: (1) refining larger, visible experiences (Start menu, File Explorer AI features) and (2) shoring up low-level reliability for PINs, input, and system settings so broader rollouts don’t create negative upgrade experiences.

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Who should install Build 27975 (and who should not)​

• Install if you are:
• An experienced Insider who tests bleeding‑edge platform behavior and can tolerate regressions.
• A developer or QA engineer tracking specific changes in input, Windows Hello, or storage UI behavior.
• Running the build on a secondary device with current backups and the ability to reimage if needed.
• Avoid if you are:
• Using your device for critical daily work where sleep/shutdown reliability, uninterrupted PIN sign-in, or the ability to roll back easily is essential.
• An enterprise admin planning wide pilots — Beta and Release Preview channels are more appropriate for controlled testing that mirrors what customers will receive.

Insider best practice remains: back up before installing Canary builds, keep a spare device for experiments, and use Feedback Hub to file repros and diagnostics for any new or lingering issues.

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Risks, mitigations, and how Microsoft is handling the pipeline​

Canary builds allow Microsoft to test early changes but bring higher risk. The key risk vectors for 27975 and related flights are:

• Regression churn — small fixes can create unexpected side effects across drivers, firmware, or other components (sleep/shutdown regressions are an example).
• Authentication regressions — Windows Hello is a critical surface; broken PIN or biometric flows cause user frustration and support incidents.
• Hardware-specific failures — issues like ARM64 kernel bugchecks or firmware/TPM incompatibilities can disproportionately affect a subset of users.

Mitigation strategies for Insiders and IT pros:

• Keep critical machines on Beta or Release Preview channels.
• For Canary testing, maintain a recovery image and system backups and ensure you have credentials to sign in if Windows Hello fails.
• Monitor the Windows Insider Blog and Microsoft’s release notes for build-specific known issues before installing.

Microsoft’s public handling has included targeted fixes in Canary (e.g., the PIN remediation in 27975), explicit known‑issue disclosures (sleep/shutdown), and coordination with tool vendors (like PIX updates for developer toolchain compatibility). These are good signs of a responsive pipeline but don’t remove the need for cautious adoption.

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Recommendation for enterprise administrators and support teams​

• Treat Canary as a research channel only — do not push Canary builds to pilot fleets.
• If you’re running focused validation (for example, validating Copilot+ features), keep affected test devices isolated and provisioned to be wiped if needed.
• Collect logs and memory dumps when PIN or power regressions occur; attach them in Feedback Hub entries to improve Microsoft’s triage speed.
• Maintain standard recovery playbooks that include alternate sign-in methods and the NGC deletion path for PIN reprovisioning — but coordinate such steps with security teams when TPM or device encryption policies are in play.

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Critical analysis — strengths and potential blind spots​

Strengths of Build 27975 and Microsoft’s current approach

• Targeted reliability work: Focusing on user-visible, high-friction problems (PIN sign-in, Settings crashes) yields high value for comparatively small changes. Fixing these reduces support overhead and improves retention of Insiders.
• Responsive triage: Microsoft’s repeated acknowledgements of sleep/shutdown and Windows Hello issues across Canary flights show that telemetry and feedback are being acted upon, even if fixes take multiple cycles.
• Parallel innovation: While fixing stability, Microsoft continues to refine large features (Start menu, AI features), which suggests a dual-track strategy that keeps feature momentum alive without ignoring reliability.

Potential risks and blind spots

• Incomplete visibility in official channels: Some lightweight Canary posts appear initially in distribution channels or community mirrors before a canonical Windows Insider Blog post is available, which can create confusion about the authoritative notes for a build. Report mirrors and community threads can be helpful but are imperfect as sole sources. If official blog notes for a given build are delayed, treat community mirrors as provisional and verify before mass adoption.
• Edge-case regressions remain: Fixing one scenario of PIN breakage doesn’t guarantee prevention of other flows that can corrupt PIN data (for example, reset flows or unusual enterprise enrollments). Ongoing vigilance and telemetry are required.
• Power-state regressions are high-risk: Sleep and shutdown regressions affect core system reliability. Until Microsoft provides a clear remediation, these remain a showstopper for using Canary on a primary device.

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Final verdict: what Build 27975 delivers — and what remains​

Build 27975 is a practical, low‑risk maintenance flight that corrects several user-facing annoyances, most importantly a Windows Hello PIN sign-in regression that had been causing interrupted sign-ins for some Insiders. For those already exploring Canary, the fixes will be welcome; for others, the build confirms Microsoft is actively stabilizing core authentication and input surfaces while continuing to iterate on larger features through the Insider pipeline.
That said, Canary remains Canary: known power-state regressions and UI oddities (Start menu scrolling) persist, and administrators should continue to pilot carefully. The broader feature roadmap (Start menu redesign, Fluid Dictation, Click to Do and other AI-driven additions) is moving forward in parallel, but 27975 reminds us that platform health and smooth upgrade paths are the foundational work that must precede any reliable, widespread feature rollout.

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End of coverage.

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Source: Windows Report Windows 11 Canary Build 27975 Fixes Issue with Windows Hello PIN