How do I manually install the Microsoft emergency patches for January 2026?

Why is my Outlook Classic freezing after the Windows 11 KB5074109 update?

Microsoft verified significant stability errors within the January 2026 Patch Tuesday deployment. These updates, released on January 13, compromised Remote Desktop connectivity, disrupted power states on older versions, and froze the Outlook Classic client.

On January 17, Microsoft deployed emergency Out-of-Band (OOB) updates to address the most critical faults. Administrators and users experiencing these specific errors must manually apply these fixes, as they are not currently pushed through standard automatic updates.

Emergency Patch Solutions

The following table details the specific patches released to resolve the Remote Desktop and Shutdown failures. You must locate the correct Knowledge Base (KB) ID for your operating system and download the .msi installer directly from the Microsoft Update Catalog.

Technical Analysis of Resolved Bugs

Remote Desktop Protocol (RDP) Authentication Failure

This error affects the “Windows App” client used to initiate connections. Following the installation of KB5074109 (Windows 11 25H2), the application fails during the credential prompt phase.

• The Technical Failure: The prompt breaks before a session establishes.
• Data Integrity: No data loss occurs because the session never starts.
• Resolution: Installing the appropriate OOB update listed above allows the credential prompt to complete the handshake.

System Guard Shutdown Loop

Devices running Windows 11 version 23H2 with “System Guard Secure Launch” enabled cannot power down correctly.

• The Symptom: Initiating a “Shut down” or “Hibernate” command triggers a system reboot instead of a power-off state.
• Impact Scope: This is limited to enterprise environments using the older 23H2 version, which is no longer supported for general consumer use.

Pending Issues and Workarounds

Microsoft has not yet released a software patch for the following identified problems. Users must utilize manual workarounds or consider rolling back the update if workflows are severely impacted.

Outlook Classic Freeze (POP Accounts)

Outlook Classic fails to launch for users utilizing POP email configurations.

• The Cause: The Outlook.exe process initializes in the background but fails to render the user interface.
• The Workaround: Open Task Manager, locate Outlook.exe, and select End Task. Relaunching the application often succeeds temporarily.
• Note: This does not affect users relying exclusively on Microsoft 365 (Exchange) accounts.

Unacknowledged System Instabilities

Technical reports indicate three additional bugs absent from Microsoft’s official known issues list:

1. Black Screen Delay: A black screen persists for several minutes before the cursor or desktop renders.
2. Wallpaper Reset: Custom desktop backgrounds revert to a solid black color, requiring reconfiguration.
3. Desktop.ini Failure: Custom folder naming conventions using desktop.ini files fail to apply.