{"family":"windows11","family_label":"Windows 11","build":"28000.3086","base":"28000","tag":"26H1","kb":"KB5124006","kb_url":"https://support.microsoft.com/help/5124006","kb_title":"September 22, 2026—KB5124006 (OS Build 28000.3086) Preview","release_date":"2026-09-22","update_type":"2026-09 D","update_type_label":"Optional preview update","servicing":"General Availability Channel","ms_known_issues":[{"title":null,"symptom":"After installing the September 8, 2026, Windows security update KB5124012 , or later updates, some Credential Guard protected machine accounts might lose their secure channel with an on-premises Active Directory (AD) domain. Users might then be unable to sign in interactively with valid domain credentials and might receive a message stating that the trust relationship between the device and the domain failed. Offline sign-in using previously cached credentials might continue to work. AD replication and AD services on the domain controllers are not affected. This issue occurs because KB5124012 and later updates enable the Machine Identity Isolation feature. While the update does not directly","workaround":"Important: This section contains information about modifying the registry. Before you modify the registry, back it up and make sure that you know how to restore it if a problem occurs. For more information, see How to back up and restore the registry in Windows . To work around this issue, disable Machine Identity Isolation using the same management method that was used to enable it. Choose the applicable option below: If Machine Identity Isolation was enabled by Intune policy, disable Machine Identity Isolation with Intune . If Machine Identity Isolation was enabled by Intune policy, disable Machine Identity Isolation with Intune . If Machine Identity Isolation was enabled by Group Policy,","applies_to":"","status":""}],"ms_none_known":false,"ms_highlights":"This update is available through two release phases: gradual rollout and normal rollout. A gradual rollout delivers an update in phases, so features reach devices over time instead of all at once, meaning availability varies by device. A normal rollout is the broad release to all eligible devices at the same time, usually when it reaches general availability (GA). Note If you installed earlier updates, your device downloads and installs only the new updates contained in this package. [Taskbar] This update gives you more ways to customize the taskbar to match how you work and make better use of screen space. New! You can now choose whether the taskbar appears at the bottom, top, left, or right side of your screen. In these other positions, tooltips, flyouts, and animations will still come from the taskbar, and most customization settings, such as never combining taskbar icons, will work with all locations. Search box and smaller taskbar are currently supported only for top and bottom positions. To change the position of the taskbar, go to Settings > Personalization > Taskbar > Taskbar behaviors > Taskbar position . New! A smaller taskbar option is now available to help maximize scre","title":"Preview Update for Windows 11 (28000.3086)","build_type":"release","channel_label":"Release","branch":null,"kind":"cumulative","kind_label":"Cumulative update","is_dotnet":false,"status":null,"line":{"status":"silicon","note":"Ships on new silicon only"},"created":1790097469,"created_iso":"2026-09-22T17:17:49Z","uuid":"5dfdb50d-719e-4f51-8eb4-1359664188d7","permalink":"/builds/windows11/28000.3086/","tag_url":"/builds/windows11/26h1/","index_url":"/builds/windows11/","api_url":"https://search.windowsforum.com/api/builds/build/windows11/28000.3086","records":[{"uuid":"5dfdb50d-719e-4f51-8eb4-1359664188d7","title":"Preview Update for Windows 11 (28000.3086)","build":"28000.3086","arch":"amd64","created":1790097469,"created_iso":"2026-09-22T17:17:49Z","build_type":"release","channel_label":"Release","branch":null,"kind":"cumulative","kind_label":"Cumulative update","status":null,"kb":null,"download_url":"https://uupdump.net/selectlang.php?id=5dfdb50d-719e-4f51-8eb4-1359664188d7"},{"uuid":"27c94336-9c4f-4563-b530-46136923ffba","title":"Preview Update for Windows 11 (28000.3086)","build":"28000.3086","arch":"arm64","created":1790097512,"created_iso":"2026-09-22T17:18:32Z","build_type":"release","channel_label":"Release","branch":null,"kind":"cumulative","kind_label":"Cumulative update","status":null,"kb":null,"download_url":"https://uupdump.net/selectlang.php?id=27c94336-9c4f-4563-b530-46136923ffba"}],"summary":"This Insider Preview delivers platform-level improvements and stability fixes for Windows 11 26H1, prioritizing specific-silicon enablement over new consumer features or major UI changes.","known_issues":[],"linked":{"news":[{"thread_id":445485,"node_id":4,"title":"KB5124006 Preview Adds Administrator Protection to Windows 11 26H1","replies":0,"views":95,"post_date":1790107993,"last_post_date":1790107993,"url":"https://windowsforum.com/news/kb5124006-preview-adds-administrator-protection-to-windows-11-26h1.445485/","kind":"coverage","match":"exact","pinned":true,"score":2.0},{"thread_id":445459,"node_id":4,"title":"KB5124006 Preview Adds Movable Taskbar, Small Size to Windows 11 26H1","replies":0,"views":119,"post_date":1790103151,"last_post_date":1790103151,"url":"https://windowsforum.com/news/kb5124006-preview-adds-movable-taskbar-small-size-to-windows-11-26h1.445459/","kind":"coverage","match":"exact","pinned":true,"score":2.0},{"thread_id":444769,"node_id":4,"title":"Windows 11 Autopilot Device Preparation Fits Entra Join Only","replies":0,"views":179,"post_date":1789626129,"last_post_date":1789626129,"url":"https://windowsforum.com/news/windows-11-autopilot-device-preparation-fits-entra-join-only.444769/","kind":"coverage","match":"exact","pinned":true,"score":2.0}],"tutorials":[],"threads":[],"total":3,"exact":3,"window_days":45},"related":{"history":[{"build":"28000.3086","title":"Preview Update for Windows 11 (28000.3086)","created":1790097469,"kb":"KB5124006","build_type":"release","channel_label":"Release","kind":"cumulative","url":"/builds/windows11/28000.3086/","current":true},{"build":"28000.3079","title":"Preview Update for Windows 11 (28000.3079)","created":1789150912,"kb":null,"build_type":"release","channel_label":"Release","kind":"cumulative","url":"/builds/windows11/28000.3079/","current":false},{"build":"28000.3076","title":"Critical OOBE Update for Windows 11 - 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