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Find information on known issues and the status of the Windows 11, version 26H1 availability. For immediate help with Windows update issues, open the Get Help app if you are using a Windows device, or go to support.microsoft.com. Follow @WindowsUpdate on X for Windows release health updates. If you are an IT administrator and want to programmatically get information from this page, use the Windows Updates API in Microsoft Graph.
Current status as of February 10, 2026
Windows 11, version 26H1 is a hardware-optimized release designed to enable next-generation silicon developed in partnership with device manufacturers and silicon partners. This release will be available exclusively as a preinstalled experience on select new devices beginning in early 2026, with capabilities tailored specifically for those platforms.
Windows 11, version 26H1 is not intended as a feature update for existing devices and will not be offered through Windows Update. Devices running Windows 11, versions 25H2 and 24H2 will continue receiving monthly security and quality updates, as well as new features, and remain supported according to servicing timelines and Microsoft lifecycle policies.
For IT admins, Windows 11, versions 25H2 and 24H2 remain the recommended releases for enterprise deployment. While Windows 11, version 26H1 is not intended for broad deployment across existing Windows 11 environments, organizations evaluating new hardware platforms may adopt it selectively without affecting their broader environment. For more information, see What to know about Windows 11, version 26H1. For servicing and lifecycle information, see Windows 11 release information, Windows Lifecycle FAQ, and Microsoft Lifecycle Policy search tool.
Known issues
See open issues, content updated in the last 30 days, and information on safeguard holds. To find a specific issue, use the search function on your browser (CTRL + F for Microsoft Edge).
| Summary | Originating update | Status | Last updated |
|---|---|---|---|
| Domain-joined devices might lose their secure trust relationship with the domain Some Credential Guard protected machine accounts might be unable to sign in interactively will valid domain credentials. | OS Build 28000.2954 KB5124012 2026-09-08 | Mitigated | 2026-09-16 14:23 PT |
| Host folder shares might be unavailable in Hyper-V-based Linux VMs Plan9 host folder shares might not appear in the guest environment after installing the September 2026 security update. | OS Build 28000.2954 KB5124012 2026-09-08 | Resolved KB5129194 | 2026-09-14 13:30 PT |
| USB audio devices might fail to start or produce no sound Some USB Audio Class 1.0 devices display Code 10 or fail in multichannel audio modes after installing KB5124008. | OS Build 28000.2954 KB5124012 2026-09-08 | Mitigated | 2026-09-14 10:57 PT |
| Remote Desktop Services might stop responding after Sept. 2026 security update Some Windows devices with Remote Desktop enabled might experience Remote Desktop Services (RDS) instability. | OS Build 28000.2954 KB5124012 2026-09-08 | Resolved KB5129194 | 2026-09-14 10:57 PT |
| Microsoft Teams and Outlook might fail to launch on ARM-based devices This most likely occurs on new PCs after installing the August Windows security update and does not affect other apps. | OS Build 28000.2704 KB5121000 2026-08-11 | Resolved KB5124012 | 2026-09-08 11:37 PT |
| Incorrect notifications that "Microsoft Defender Antivirus is turned off" Microsoft Defender Antivirus remains active and functioning correctly despite notifications following the latest update. | N/A | Confirmed | 2026-08-28 16:02 PT |
Issue details
September 2026
Domain-joined devices might lose their secure trust relationship with the domain
| Status | Originating update | History |
|---|---|---|
| Mitigated | OS Build 28000.2954 KB5124012 2026-09-08 | Last updated: 2026-09-16, 14:23 PT Opened: 2026-09-16, 14:15 PT |
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 enable Machine Identity Isolation enforcement, it does cause Windows to begin honoring any existing or policy-provisioned settings that enabled Machine Identity Isolation enforcement. However, this feature is only supported for environments connected to domain controllers running at a Windows Server 2025 Domain Functional Level (DFL) and above. The feature should be disabled elsewhere. Any devices previously configured to use Machine Identity Isolation that are not connected to Windows Server 2025 domain controllers will experience this issue and will need to disable the feature.
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 group policy, disable Machine Identity Isolation with group policy.
- If Machine Identity Isolation was enabled directly in the registry, use these steps to disable it:
- On the Windows 11, version 24H2 or 25H2 device, locate the following registry paths:
- HKLM\SYSTEM\CurrentControlSet\Control\Lsa\MachineIdentityIsolation
- HKLM\SOFTWARE\Policies\Microsoft\Windows\DeviceGuard\MachineIdentityIsolation
- For either of these registry keys, if the value for MachineIdentityIsolation = 2, then set MachineIdentityIsolation = 0.
After you disable Machine Identity Isolation, restart the device.
Then reset the secure channel using the following command:
'Test-ComputerSecureChannel -Repair -Credential (Get-Credential)'
Next Steps: We plan to resolve this issue in a future Windows update by temporarily preventing Machine Identity Isolation enforcement while improvements are made to the feature.
Affected platforms:
Client: Windows 11, version 26H1; Windows 11, version 25H2; Windows 11, version 24H2
Server: None
Host folder shares might be unavailable in Hyper-V-based Linux VMs
| Status | Originating update | History |
|---|---|---|
| Resolved KB5129194 | OS Build 28000.2954 KB5124012 2026-09-08 | Resolved: 2026-09-14, 10:00 PT Opened: 2026-09-11, 02:22 PT |
Updated (9/14): The resolution section was updated. IT administrators that deployed a temporary mitigation through Group Policy must re-enable the Group Policy and install the out-of-band update to resolve the issue.
After installing the September 2026 security update KB5124012, applications that use HCS-managed virtual machines might experience issues when sharing host folder with Linux VMs using Plan9. Affected virtual machines start normally, but folders shared from the Windows host using Plan9 do not appear or cannot be accessed in the guest environment.
Applications or sandbox environments that depend on these shared folders might display an error indicating that no Plan9 drive shares were mounted. Claude Cowork and the Windows Subsystem for Linux (WSL) are two of the applications affected by this issue. Standard Hyper-V virtual machines that do not use the Plan9 feature are not affected by this issue.
Resolution: This issue is resolved by the out-of-band (OOB) update released on September 14, 2026 (KB5129194), and in updates released after this date.
IT administrators who deployed a temporary mitigation through Group Policy must re-enable the Group Policy, install this OOB update, and restart to resolve this issue.
This OOB update is cumulative and includes all improvements and security protections contained in previous Windows updates. As a best practice, we recommend installing the latest update available for your devices, as it contains important improvements and issue resolutions, including this one.
Affected platforms:
- Client: Windows 11, version 26H1; Windows 11, version 25H2; Windows 11, version 24H2; Windows 11, version 23H2; Windows 10, version 22H2; Windows 10, version 21H2
- Server: None
Click here to manage email notifications for Windows known issues.
USB audio devices might fail to start or produce no sound
| Status | Originating update | History |
|---|---|---|
| Mitigated | OS Build 28000.2954 KB5124012 2026-09-08 | Last updated: 2026-09-14, 10:57 PT Opened: 2026-09-11, 18:36 PT |
After installing the September 8, 2026, Windows security update (KB5124012), some USB Audio Class 1.0 devices might fail to start or produce audio. Affected devices might experience one or more of the following symptoms:
- The device displays an error in Device Manager: "This device cannot start (Code 10).”
- No audio output.
- Volume controls are unresponsive or remain at zero.
- Sound settings are unresponsive or unavailable.
- Some devices might function in standard stereo configurations but fail when using multichannel audio features, including 8-channel or 3D audio modes. Some customers have reported that they're able to restore audio in these cases by switching to 2-channel mode. (*Note: This behavior is resolved in the out-of-band update released on September 14, 2026. See Resolution section below.)
This issue is limited to USB Audio Class 1.0 devices.
Microsoft Support: IT administrators who need an immediate workaround for the symptoms not addressed yet by the OOB update should contact Microsoft Support for Business for assistance.
Resolution: This issue is partially resolved in the out-of-band (OOB) update released on September 14, 2026, (KB5129194), and updates released after this date. This OOB update resolves the symptoms experienced on devices using 8-channel or 3D audio modes (last bullet point in the list of symptoms documented in this entry). We are working to address the other symptoms and will update this documentation when more information is available.
Affected platforms:
- Client: Windows 11, version 26H1; Windows 11, version 25H2; Windows 11, version 24H2; Windows 11, version 23H2; Windows 10, version 22H2; Windows 10, version 21H2; Windows 10 Enterprise LTSC 2019; Windows 10 Enterprise LTSC 2016
- Server: Windows Server 2025; Windows Server 2022; Windows Server 2019; Windows Server 2016; Windows Server 2012 R2; Windows Server 2012
Remote Desktop Services might stop responding after Sept. 2026 security update
| Status | Originating update | History |
|---|---|---|
| Resolved KB5129194 | OS Build 28000.2954 KB5124012 2026-09-08 | Resolved: 2026-09-14, 10:00 PT Opened: 2026-09-11, 11:19 PT |
After installing the September 2026 Windows security update (KB5124012), some organizations might experience issues with Remote Desktop Services (RDS).
In some environments, RDS might become unstable, resulting in RDP connections failing after several minutes, sign-in issues, or servers hanging at "Please wait for the Remote Desktop Configuration". Related tools, including Microsoft Management Console (MMC), RDS Licensing Diagnoser, and File Explorer might also become unresponsive. Additionally, the Windows Update page might stop responding and continuously display a loading indicator.
Resolution: This issue is resolved by the out-of-band (OOB) update released on September 14, 2026 (KB5129194), and in updates released after this date.
IT administrators who deployed a temporary mitigation through Group Policy do not need to take any action before installing this OOB update.
This OOB update is cumulative and includes all improvements and security protections contained in previous Windows updates. As a best practice, we recommend installing the latest update available for your devices, as it contains important improvements and issue resolutions, including this one.
Affected platforms:
- Client: Windows 11, version 26H1; Windows 11, version 25H2; Windows 11, version 24H2; Windows 11, version 23H2; Windows 10, version 22H2; Windows 10, version 21H2; Windows 10 Enterprise LTSC 2019; Windows 10 Enterprise LTSC 2016
- Server: Windows Server 2025; Windows Server 2022; Windows Server 2019; Windows Server 2016; Windows Server 2012 R2; Windows Server 2012
Microsoft Teams and Outlook might fail to launch on ARM-based devices
| Status | Originating update | History |
|---|---|---|
| Resolved KB5124012 | OS Build 28000.2704 KB5121000 2026-08-11 | Resolved: 2026-09-08, 10:00 PT Opened: 2026-09-01, 18:46 PT |
After installing Windows security updates released on or after August 11, 2026, (KB5121000), Microsoft Teams and the new Outlook for Windows might fail to launch or might close unexpectedly on ARM-based devices, such as Surface Pro 11 and Surface Laptop 7. Classic Outlook, Word, Excel, and other applications are not known to be affected. This issue is most likely to occur on new or freshly imaged PCs that have not yet installed any Microsoft Store updates.
Resolution: This issue was resolved by Windows updates released September 8, 2026 (KB5124012), and updates released after that date. We recommend you install the latest update for your device as it contains important improvements and issue resolutions, including this one.
If you install an update released September 8, 2026 (KB5124012), or later, you do not need to use a workaround for this issue. If you are using an update released before September 8 and have this issue, you have the option to apply the following workaround.
Workaround: To work around this issue:
- Open Microsoft Store.
- Select Downloads > Check for updates.
- Install the latest update for the Auto Super Resolution Package (version 1.0.19.0 or later).
Affected platforms:
- Client: Windows 11, version 26H1; Windows 11, version 25H2; Windows 11, version 24H2
- Server: None
August 2026
Incorrect notifications that "Microsoft Defender Antivirus is turned off"
| Status | Originating update | History |
|---|---|---|
| Confirmed | N/A | Last updated: 2026-08-28, 16:02 PT Opened: 2026-08-28, 15:34 PT |
After installing the latest updates for Microsoft Defender Antivirus, notifications might appear stating that "Microsoft Defender Antivirus is turned off," even though the antivirus is functioning correctly and all settings show it as active. These notifications can appear when Windows starts and intermittently afterward. They persist even if notification settings are turned off.
This issue can be observed in any version of Windows or Windows Server with Microsoft Defender Antivirus running with the latest Defender updates.
Next steps: We are working to release a resolution in a future Microsoft Defender Antivirus update and will provide more information when it is available.
Affected platforms:
- Client: Windows 11, version 26H1; Windows 11, version 25H2; Windows 11, version 24H2; Windows 11, version 23H2; Windows 10, version 22H2; Windows 10, version 21H2; Windows 10 Enterprise LTSC 2019; Windows 10 Enterprise LTSC 2016
- Server: Windows Server 2025; Windows Server 2022; Windows Server 2019; Windows Server 2016; Windows Server 2012 R2; Windows Server 2012
Report a problem with Windows updates
To report an issue to Microsoft at any time, use the Feedback Hub app. To learn more, see Send feedback to Microsoft with the Feedback Hub app.
Need help with Windows updates?
Search, browse, or ask a question on the Microsoft Support Community. If you are an IT pro supporting an organization, visit Windows release health on the Microsoft 365 admin center for additional details.
For direct help with your home PC, use the Get Help app in Windows or contact Microsoft Support. Organizations can request immediate support through Support for business.
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