Visual Regression: Boot and login animation reverted to legacy dots after KB5127936 (Build 26300.9818)

Report this as a Problem through Feedback Hub and attach diagnostics, because the animation regression has matching public reports but is not currently listed as an acknowledged Windows 11 26H2 known issue or given a supported workaround.

KB5127936 is the October 28, 2026 preview update for Windows 11 26H2/25H2, producing builds 26300.9818 and 26200.9818.^1^ A separate report describes the same Progressive Ring-to-legacy-dots change on build 26300.9818.^2^

Submit an actionable bug report

1. Press Windows key + F to open Feedback Hub.
2. Sign in so that you can search existing reports and track your submission.
3. Search for terms such as:
   • 26300.9818 boot animation legacy dots
   • KB5127936 Progressive Ring
4. If an exact report appears, select Upvote and Give similar feedback. Otherwise, select Give new feedback.
5. Select Problem, not Suggestion, and use a specific title such as: KB5127936 build 26300.9818 replaces Progressive Ring with legacy dotted boot and sign-in animation
6. Include these details:
   • Windows 11 Pro Insider Preview, version 26H2
   • Build 26300.9818
   • Update KB5127936
   • The modern animation appeared before the update
   • The legacy dotted animation appeared immediately after installation and restart
   • The behavior affects startup, restart, and sign-in
   • The BootProgressAnimation DWORD did not change the behavior
7. Attach before-and-after images or a short external video if available. Feedback Hub supports screenshots, files, and diagnostic recordings.^3^
8. Enable the option to send attached diagnostics, save a local copy if desired, and select Submit.
9. Copy the resulting Feedback Hub link and add it to the Q&A post so other affected Insiders can upvote the same report rather than fragmenting reports.

Current status

Microsoft’s Windows 11 26H2 release-health page does not currently list this boot/sign-in animation regression among the published known issues.^4^ The KB5127936 release notes also do not document a fix or workaround for it.

The Insider notes state that changes in this update can use gradual rollout, meaning availability may vary by device.^5^ However, the published notes do not identify the boot animation as a staged feature, so gradual rollout alone does not establish the cause.

Since the registry modification already failed and no supported registry workaround is documented for this build, further changes under BootControl are not recommended. Monitor Feedback Hub → My feedback, the 26H2 release-health page, and subsequent cumulative-update notes for acknowledgment or a fix. Feedback Hub is the supported channel for getting an Insider regression and its diagnostics to Windows engineering; Microsoft Q&A cannot schedule a cumulative-update fix.

References

1. October 28, 2026— KB5127936 (OS Builds 26300.9818 and 26200.9818 ...
2. Boot and login animation regression to old dots ring after installing ...
3. Send feedback to Microsoft with the Feedback Hub app | Microsoft Support
4. Windows 11, version 26H2 known issues and notifications
5. Windows 11 Insider Release Preview Build 26200.9807/26300.9807