Microsoft released the January 13, 2026 cumulative update KB5074109 for Windows 11 versions 25H2 and 24H2, advancing affected systems to OS builds 26200.7623 and 26100.7623. This update includes the latest security fixes and quality improvements, as well as non-security changes that were previously offered in an optional preview. Microsoft also standardized update titles for clarity and separated Windows Server 2025 update identifiers from Windows 11’s. A key advisory notes that Windows Secure Boot certificates are set to expire starting June 2026, and users should review guidance to avoid boot issues. The release continues Microsoft’s monthly cumulative update model, designed to keep Windows 11 devices secure and up to date with the latest fixes.
Microsoft confirmed a problem with Windows 365 after a recent service update caused users to be unable to connect to their Cloud PC sessions. The issue began Tuesday around 19:00 UTC, and users started reporting sign-in failures and intermittent access problems when attempting to start their Cloud PCs.
Windows 365 is Microsoft’s cloud PC service that runs on Azure Virtual Desktop, letting enterprise and business customers stream a full Windows experience from the cloud.
Microsoft’s Response
Microsoft’s monitoring systems detected a surge in failed connection attempts and traced the issue back to one of the recent Windows 365 updates. According to the incident report:
- The update was intended to improve security functionality.
- It ended up causing connection failures when users tried to access their Cloud PC sessions.
- Engineers are analyzing the update to determine how to mitigate the impact.
At this early stage, there’s no official wide-scale fix rolled out yet — but Microsoft is investigating.
How This Relates to Other Microsoft Issues
While this specific Windows 365 issue is separate, Microsoft services have seen other widespread interruptions in recent months — including an outage affecting Azure, Microsoft 365 apps, Xbox services, and more. These incidents highlight ongoing challenges with cloud-based infrastructure scale and reliability.
What Affected Users Can Do
If you or your users are facing access problems, here are a few things to keep in mind (based on Microsoft’s Cloud PC service requirements and known troubleshooting guidance):
1. Check Windows 365 Service Health
Enterprise admins should review the Microsoft 365 admin center service health dashboard — this will show real-time alerts and detailed error data from Microsoft.
2. Verify Client Software
Make sure users are connecting via the supported Windows 365/Windows App clients. Older Remote Desktop clients (like the legacy Microsoft Remote Desktop) are being phased out and may not work consistently.
3. Connection Troubleshooting
If users partially connect or see errors, some helpful steps include:
- Running the Inspect Connection tool in the Windows App.
- Reviewing network policies or VPN configurations that could interfere with the Cloud PC connection.
Admin-Level Considerations
Enterprise customers should also watch for configuration and policy updates, especially around Conditional Access and authentication — these sometimes affect sign-in behavior for Cloud PCs.
Bottom line: A recent Windows 365 update is causing failed connection attempts to Cloud PC sessions, and Microsoft is actively investigating. This is affecting enterprise users globally, and fixes or mitigations are expected as Microsoft analyzes the update
