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Windows Server 2025 known issues and notifications
Find information on known issues and the servicing status for Windows Server 2025. 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.
Current status as of November 1, 2024
Windows Server 2025 is now generally available. It delivers security advancements and new hybrid cloud capabilities in a high performing, AI-capable platform. Windows Server 2025 is Microsoft’s latest Long-Term Servicing Channel (LTSC) release for Windows Server. To download a free 180-day evaluation, visit the Microsoft Evaluation Center.
To learn more about Windows Server’s Lifecycle Policy, see the Windows Server 2025 lifecycle article.
- Get Windows Server known issues in Graph API
Data is available for supported Windows Server versions
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 |
|---|---|---|---|
| Some text might appear in English during the installation process This only occurs when utilizing certain media, such as CD or USB, to install Windows Server 2025 | N/A | Confirmed | 2024-11-01 10:05 PT |
| Windows Server 2025 might not run as expected on devices with high core count This is observed on servers with 256 or more logical processors. Issues may not trigger consistently. | N/A | Confirmed | 2024-11-01 10:05 PT |
| Error 'boot device inaccessible' might appear in iSCSI environments Servers might see error 'boot device inaccessible' after the installation of Windows Server 2025 | N/A | Confirmed | 2024-11-01 10:05 PT |
Issue details
October 2024
Some text might appear in English during the installation process
| Status | Originating update | History |
|---|---|---|
| Confirmed | N/A | Last updated: 2024-11-01, 10:05 PT Opened: 2024-10-31, 13:12 PT |
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).
Next steps: We are working on a resolution and will provide more information when it is available.
Affected platforms:
- Client: None
- Server: Windows Server 2025
Windows Server 2025 might not run as expected on devices with high core count
| Status | Originating update | History |
|---|---|---|
| Confirmed | N/A | Last updated: 2024-11-01, 10:05 PT Opened: 2024-10-31, 13:11 PT |
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.
Workaround: To temporarily work around 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:
- Restart your server and enter the UEFI Setup. Navigate through the firmware menus, which may vary by manufacturer.
- Locate any option which allows you to adjust the number of cores per socket.
- 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.
- Restart the server.
Next steps: We are working on a resolution, and it will be available in future Windows monthly update.
Affected platforms:
- Client: None
- Server: Windows Server 2025
Error 'boot device inaccessible' might appear in iSCSI environments
| Status | Originating update | History |
|---|---|---|
| Confirmed | N/A | Last updated: 2024-11-01, 10:05 PT Opened: 2024-10-31, 16:09 PT |
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.
Next steps: We are working on a resolution, and it will be available in future Windows monthly update.
Affected platforms:
- Client: None
- Server: Windows Server 2025
Report a problem with Windows updates
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Need help with Windows updates?
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