Microsoft has addressed a series of bugs affecting the installation, upgrade, and functionality of Windows Server 2025, particularly on devices boasting a high core count. Users have reported symptoms ranging from installation failures and prolonged upgrade processes to excessive boot times, sometimes extending to three hours or more. Additionally, the notorious Blue Screen of Death (BSOD) has been a frustrating occurrence for many, manifesting during app launches, restarts, or general usage.
Identifying Affected Systems
According to Microsoft’s updates on the Windows release health dashboard, these issues do not consistently affect all devices within the impacted category. To determine if your Windows Server 2025 system is among those affected, users can utilize the CTRL+SHIFT+ESC keyboard shortcut to access the Windows Task Manager. By navigating to the Performance tab, one can check for the presence of over 256 logical processors.
“This issue was resolved by Windows updates released November 12, 2024 (KB5046617), and later,” the company stated. “We recommend you install the latest security update for your device as it contains important improvements and issue resolutions, including this one.”
Temporary Workaround
For those unable to implement the KB5046617 November Patch Tuesday cumulative update immediately, Microsoft has provided a temporary workaround. Administrators can limit the number of logical processors on affected devices to fewer than 256. The following steps outline how to adjust the active logical processors:
- Restart your server and enter the UEFI Setup. Navigate through the firmware menus, which may vary by manufacturer.
- Locate any option that 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 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.
“Changing the number of logical processors will vary depending on the firmware installed on your device,” the company added.
Ongoing Investigations
In addition to these fixes, Microsoft is actively investigating another issue with Windows Server 2025 that is causing boot problems in iSCSI environments, leading to “boot device inaccessible” errors on affected systems. This comes on the heels of last week’s announcement that Windows Server 2025 is now generally available, with a complimentary 180-day trial accessible through the Microsoft Evaluation Center.
As the latest Long-Term Servicing Channel (LTSC) release for Windows Server, Windows Server 2025 represents a significant step forward for Microsoft, promising enhanced stability and performance for enterprise users.
