​Microsoft has confirmed several bugs causing installation and Blue Screen of Death (BSOD) issues affecting Windows Server 2025 systems with more than 256 logical processors.

Users may experience symptoms such as Windows Server 2025 installation or upgrade processes failing or hanging and the server starting and restarting taking up to three hours or more in some cases.

They may also see blue screens when launching, restarting, or trying to run an application on affected servers.

However, as the company explains in a new entry on Windows version healthThese issues do not trigger consistently on affected devices.

To determine if these known issues affect any of your Windows Server 2025 systems, open Windows Task Manager using the keyboard shortcut CTRL+SHIFT+ESC and check if it shows more than 256 logical processors in the tab Performance.

Redmond is working on a fix, which will ship with an upcoming Windows monthly update. Until a solution is available, administrators can work around these issues by limiting the number of logical processors on affected devices to 256 or less.

To adjust the number of active logical processors, you can follow these instructions:

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

It is also customers notified that they might see text appear in English during installation when using certain media, such as a CD or USB flash drive, to install Windows Server 2025, regardless of the language selected.

This only occurs when using Multilingual User Interface (MUI) on Windows Server media 25100.1742 and later.

Microsoft released the first version of Windows Server 2025 for Windows Insider Program administrators in January, introducing next-generation Active Directory, hotpatching, and SMB alternate ports on QUIC, which allow switching from the default SMB port on QUIC UDP/443 to any other port.

The company announced this weekend that Windows Server 2025 is now available to everyone, with a 180-day free trial available through the Microsoft Assessment Center.

Windows Server 2025 is now Microsoft’s latest Long-Term Servicing Channel (LTSC) release for Windows Server.