Resolved issues in Windows Server 2025

Find information on recently resolved issues for Windows Server 2025. To find a specific issue, use the search function on your browser (CTRL + F for Microsoft Edge). For immediate help with Windows update issues, click here if you are using a Windows device to open the Get Help app 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.

Resolved issues

Issue details

April 2025

Authentication issues due to failed password rotation in Kerberos

After installing Windows Server 2025, devices using the Identity Update Manager certificate/Public Key Cryptography for Initial Authentication (PKNIT), might experience an issue with passwords not rotating correctly, causing authentication failures. This issue occurs particularly when Kerberos Authentication is used and the Credential Guard feature is enabled. Note that machine certification using PKINIT path is a niche use case, and this issue affects a small number of devices in enterprise environments.

With this issue, devices fail to change their password every 30 days as the default interval. Because of this failure, devices are perceived as stale, disabled, or deleted, leading to user authentication issues. 

Devices running Windows Home edition are unlikely to be affected by this issue, as Kerberos authentication is typically used in enterprise environments and is not common in personal or home settings. 

Resolution:  

This issue is resolved in the April 2025 Windows security update (KB5055523) and later updates. We recommend you install the latest update for your device as it contains important improvements and issue resolutions, including this one. 

Note: The feature Machine Accounts in Credential Guard, which is dependent on password rotation via Kerberos, has been disabled until a permanent fix is made available. 

Affected platforms:

• ​Client: Windows 11, version 24H2

• ​Server: Windows Server 2025

October 2024

Some text might appear in English during the installation process

When installing Windows Server 2025, some text might appear in English during the installation process, regardless of the language selected for the installation. This will be noticeable if a language other than English has been selected for installation.

Please note, this only occurs when utilizing media - such as CD and USB flash drives - to install Windows Server 2025. This issue is only present on Windows Server media 25100.1742 and above with the use of Multilanguage User Interface (MUI).

Resolution: This issue was resolved by Windows updates released April 8, 2025 (KB5055523), and later. We recommend you install the latest security update for your device as it contains important improvements and issue resolutions, including this one. 

Affected platforms:

• ​Client: None
• ​Server: Windows Server 2025

Error 'boot device inaccessible' might appear in iSCSI environments

Servers which use iSCSI (Internet Small Computer Systems Interface) technology might display an error upon startup, with the message 'boot device inaccessible'.  

This is observed on servers operating under NDIS Poll Mode booting from an iSCSI LUN. Under such configuration, the server will experience the error during startup, after the installation of Windows Server 2025 is completed.

Resolution: This issue was resolved by Windows updates released February 11, 2025 (KB5051987), and later. We recommend you install the latest update for your device as it contains important improvements and issue resolutions, including this one.

Affected platforms:

• ​Client: None
• ​Server: Windows Server 2025

Windows Server 2025 might not run as expected on devices with high core count

Servers which have a high number of logical processors might experience issues running Windows Server 2025. This is presently observed on servers which have 256 or more logical processors.

On these devices, one or more of the following issues might be encountered:

• ​Windows Server 2025 installation or upgrading processes might fail or stop responding.
• ​Starting or restarting Server might take an excessive amount of time, such as 3 hours or more.
• ​An error message on a blue screen appears when starting, restarting, or trying to run an application.

Issues may not trigger consistently, for which it is also possible that the server will start and operate without problem.

To determine whether you are encountering this issue because the number of logical processors on the device exceeds 256, open the Windows Task Manager. This can be accomplished by pressing CTRL+SHIFT+ESC. From there, select the Performance tab and note the number of logical processors reported in the bottom half of the window.

Resolution: This issue was resolved by Windows updates released November 12, 2024 (KB5046617), and later. We recommend you install the latest security update for your device as it contains important improvements and issue resolutions, including this one. If you install an update released November 12, 2024 (KB5046617) or later, you do not need to use a workaround for this issue. If you are using an update released before this date, and have this issue, you have the option to apply the following workaround:

To temporarily prevent this issue, you will need to limit the total number of logical processors on the server to 256 or under. Changing the number of logical processors will vary depending on the firmware installed on your device.

To adjust the number of logical processors, follow these steps:

1. ​Restart your server and enter the UEFI Setup. Navigate through the firmware menus, which may vary by manufacturer.
2. ​Locate any option which allows you to adjust the number of cores per socket.
3. ​Set the number of cores per socket to a value that ensures the total number of logical processors is 256 or fewer. Important: The total number of logical processors is calculated by first multiplying the number of sockets by the number of cores per socket, and then multiplying that result by the number of logical processors per core.
4. ​Restart the server.

Affected platforms:

• ​Client: None
• ​Server: Windows Server 2025

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