Microsoft closes book on rogue Windows Server 2025 upgrades

Starts new one on boot loops

More than a year after giving administrators an unwelcome surprise with a security update that turned out to be a Windows Server 2025 upgrade, Microsoft has marked the incident as "resolved."

As far as Microsoft was concerned, the issue was "mitigated" shortly after being reported, but it has taken the company well over a year to declare it resolved. The fix came with KB5082063, a cumulative update that, in true Microsoft style, has problems of its own.

The issue that emerged in 2024 was every sysadmin's nightmare. Affected Windows Servers were quietly and automatically upgraded to Windows Server 2025. Worse, there was no obvious way to roll things back.

Microsoft blamed this on third-party products used to manage updates for clients and servers. The company said: "The Windows Server 2025 feature update was released as an Optional update under the Upgrade Classification: 'DeploymentAction=OptionalInstallation'. Feature update metadata must be interpreted as Optional and not Recommended by patch management tools."

The company's explanation at the time did not sit well with some vendors and administrators, and several Register readers told us that servers not running any third-party update services still received an overnight surprise upgrade.

More than a year later, Microsoft has set the "Resolved" flag thanks to a cumulative update that also introduces another issue. It said: "After installing this update, non‑Global Catalog (non‑GC) domain controllers (DCs) in environments that use Privileged Access Management (PAM) might experience LSASS crashes during startup.

"As a result, affected DCs might restart repeatedly, preventing authentication and directory services from functioning, and potentially rendering the domain unavailable."

Repeated domain controller reboots are unlikely to reassure administrators already concerned about update quality. Microsoft has promised a fix for the problem "in the next coming days."

The company has had a difficult few months in terms of software quality. This is despite Windows boss Pavan Davuluri penning a lengthy post intended to reassure users that Microsoft was working to improve reliability.

Instead, it appears to have continued to introduce new and exciting ways for the operating system to fall over, even in server guise.

Still, it has at least addressed the problem of Windows Server 2025 turning up uninvited, even if it took over a year. ®