Windows Server 2025 is now available – but Microsoft warns admins to watch out for three major bugs, including one that causes the dreaded blue screen of death

Microsoft has released the latest version of its server operating system, Windows Server 2025 — but it comes alongside a trio of bugs.

Windows Server 2025 is Microsoft’s latest version of its server OS, following on from Windows Server 2022. The new version is arriving alongside System Center 2025, which Microsoft said means it’s possible to “make the most” of new features immediately.

The tech giant promises better security, performance, and “cloud agility” with the latest version, but warned admins to be wary of three bugs during the installation process that include an issue that causes blue screen errors in systems with a high core count.

“Generally available today, Windows Server 2025 builds on our mission to deliver a secure and high-performance Windows Server platform tailored to meet customers’ diverse needs,” wrote Ian LeGrow, corporate vice president for Azure Edge and Platform, in a blog post.

“This release will enable you to deploy apps in any environment, whether on-premises, hybrid environments, or in the cloud.”

Key features in Windows Server 2025

On the security front, Microsoft has beefed up security in Active Directory, including new cryptographic support, and added new techniques for preventing a range of attacks against server message block (SMB), including hardened firewall defaults and protections against brute force, spoofing, and man in the middle attacks.

For cloud users, Microsoft highlighted a few notable features, such as hotpatching for hybrid and on-prem clouds, though this will require an additional subscription fee.

“Customers operating fully in the cloud have inherent modern security advantages like automatic software updates and back-up and recovery,” LeGrow wrote.

“Now we’re bringing some of those capabilities to Windows Server 2025 for on-premises customers with a new hotpatching subscription service, enabled by Azure Arc. With hotpatching, customers will experience fewer reboots and minimal disruption to operations.”

Alongside that, Microsoft has integrated Azure Arc for easier onboarding and operational flexibility, unified network policy management, and software-defined network multisite features for easier migration and management.

Microsoft of course can’t fail to mention AI. LeGrow said Windows Server 2025 was designed for demanding workloads including AI and machine learning.

“Windows Server 2025 delivers up to 60% more storage IOPs performance compared to Windows Server 2022 on identical systems,” he said. “Windows Server 2025 introduces massive performance and scalability improvements that come from Azure.”

Alongside the new features, Microsoft is also killing off a few. That includes WordPad, Windows PowerShell 2.0 engine, and the SMTP service.

Watch out for the bugs

Microsoft has warned about three particular issues that may crop up during installation. The tech giant confirmed it is working on addressing all three bugs, which have varying levels of seriousness.

The first bug might show English text during installation, regardless of the language selected. As Microsoft points out, that won’t affect English-language users, but “will be noticeable if a language other than English is selected for installation.”

However, this error only happens if using a CD or USB drive to install Windows Server 2025.

The second means Windows Server 2025 might not run properly on devices with a high core count. Microsoft said it appears to be happening on servers with more than 256 cores, and is causing the installation or upgrade to fail or stop, long restarts of three hours or more, and a blue screen error.

The issue doesn’t seem to happen on all systems with high core counts, but if it does, limit the number of cores below 256 for installation.

Finally, the third issue includes an error saying “boot device inaccessible” may be displayed in iSCSI environments during startup after installation of Windows Server 2025.

Key details

Windows Server 2025 is available immediately, alongside System Centre 2025. As a long-term release, it will have extended support until 2034, and mainstream support until 2029.

It is possible to upgrade directly to Windows Server 2025 from as far back as Windows Server 2012 R2. Windows Server 2022 will be supported until October 2026.

Windows Server 2025 will work with most 64-bit processors, and Microsoft has released a full list of certified processors.