Introduction

Windows Server 2025, Microsoft's latest Long-Term Servicing Channel (LTSC) release, introduces advanced features aimed at enhancing performance, security, and cloud integration. However, administrators have encountered several issues that require attention. This article provides an in-depth analysis of these challenges, their implications, and the solutions available.

Key Issues and Workarounds

1. High-Core Systems Installation and Upgrade Challenges

Issue:

Servers equipped with more than 256 logical processors have experienced installation failures, prolonged startup times (exceeding three hours), and Blue Screen of Death (BSOD) errors during startup or application execution. These issues occur inconsistently, complicating diagnosis and resolution.

Identification:

To determine if a system is affected:

  • Open Task Manager (Ctrl+Shift+Esc).
  • Navigate to the Performance tab.
  • Check if the number of logical processors exceeds 256.
Workaround:

Until a permanent fix is implemented:

  1. Restart the server and enter the UEFI Setup.
  2. Locate the option to adjust the number of cores per socket.
  3. Set the number of cores per socket to ensure the total logical processors do not exceed 256.
  4. Restart the server to apply changes.
Note: This workaround is detailed in Microsoft's release health dashboard. (learn.microsoft.com)

2. Remote Desktop Session Freezes Post-February 2025 Update

Issue:

After installing the February 2025 security update (KB5051987), Remote Desktop Protocol (RDP) sessions may freeze shortly after connection. This results in unresponsive mouse and keyboard inputs, necessitating frequent disconnections and reconnections.

Resolution:

Microsoft has acknowledged this issue and released updates to address it. Administrators are advised to install the latest updates to resolve the problem. For more details, refer to Microsoft's release health dashboard. (learn.microsoft.com)

3. Authentication Issues Due to Failed Password Rotation in Kerberos

Issue:

Devices using the Identity Update Manager certificate/Pre-Bootstrapping Key Initialization (PKINIT) protocol may experience password rotation failures, leading to authentication issues. This is particularly prevalent when Kerberos Authentication is used alongside the Credential Guard feature.

Resolution:

This issue was resolved in the April 2025 Windows security update (KB5055523). Administrators should install the latest updates to ensure system stability. (support.microsoft.com)

4. Language Display Issues During Installation

Issue:

During installation, some text may appear in English regardless of the selected language. This occurs when using certain media formats, such as CDs or USB drives, and does not affect English-language installations.

Resolution:

This issue was resolved in the April 2025 Windows security update (KB5055523). Administrators should install the latest updates to ensure system stability. (support.microsoft.com)

Implications and Impact

These issues can significantly impact server performance, user experience, and administrative efficiency. Prolonged downtimes, authentication failures, and installation challenges can disrupt business operations and compromise security. It is crucial for administrators to stay informed about these issues and apply the recommended updates and workarounds promptly.

Technical Details

  • High-Core Systems:
    • Logical Processors: Servers with more than 256 logical processors are susceptible to installation and performance issues.
    • UEFI Settings: Adjusting the number of cores per socket in the UEFI setup can mitigate these issues temporarily.
  • Remote Desktop Freezes:
    • Security Update KB5051987: Identified as the cause of RDP session freezes.
    • Update KB5055523: Released to resolve the freezing issue.
  • Kerberos Authentication Failures:
    • PKINIT Protocol: Involves the use of certificates for initial authentication.
    • Credential Guard: A security feature that, when combined with PKINIT, may lead to password rotation failures.
  • Installation Language Issues:
    • Media Formats: Certain installation media may display English text regardless of the selected language.
    • Multilanguage User Interface (MUI): The issue is present in Windows Server media 25100.1742 and above with MUI.

Conclusion

While Windows Server 2025 offers numerous enhancements, administrators must be vigilant about the known issues and their resolutions. Regularly updating systems and applying the recommended workarounds will ensure optimal performance and security.

Reference Links

  1. Windows Server 2025 Known Issues and Notifications
  • URL: (learn.microsoft.com)
  • Source: Microsoft Learn
  • Description: Official documentation detailing known issues and notifications for Windows Server 2025.
  1. Resolved Issues in Windows Server 2025
  • URL: (learn.microsoft.com)
  • Source: Microsoft Learn
  • Description: A list of issues that have been resolved in Windows Server 2025.
  1. April 8, 2025—KB5055523 (OS Build 26100.3775)
  • URL: (support.microsoft.com)
  • Source: Microsoft Support
  • Description: Details about the April 8, 2025, security update addressing various issues in Windows Server 2025.
  1. Recent Windows Server 2025 Updates Cause Remote Desktop Freezes
  • URL: (bleepingcomputer.com)
  • Source: BleepingComputer
  • Description: An article discussing the impact of recent updates on Remote Desktop functionality in Windows Server 2025.
  1. Microsoft Fixes Bugs Causing Windows Server 2025 Blue Screens, Install Issues
  • URL: (bleepingcomputer.com)
  • Source: BleepingComputer
  • Description: Coverage of Microsoft's resolution of critical bugs affecting Windows Server 2025 installations and performance.