When Microsoft debuted Windows Server 2025 in late 2024, the company highlighted hotpatching as a key capability, promising fewer disruptive reboots for critical infrastructure – a long-standing pain point for administrators.
Enabled through Azure Arc, Microsoft’s platform for extending management to servers outside its own cloud, the feature appeared set to offer significant operational relief. Now, the plan is shifting: beginning July 1, 2025, utilizing hotpatching on Windows Server 2025 Standard and Datacenter editions within on-premises and multicloud environments will require a paid subscription, as Microsoft has now announced.
A Price Tag on Reduced Downtime
The subscription fee is set at $1.50 per CPU core, billed monthly. This change directly impacts organizations running the latest server OS on their own hardware or in other clouds who want to use the reboot-minimizing update technology.
Connection through Azure Arc remains a prerequisite for the service, although Microsoft clarifies that the Arc connection itself, when used solely for enabling hotpatching, does not add extra costs. This move transitions the feature from its currently free preview status, which is scheduled to end on June 30, 2025. Administrators participating in the preview must actively opt out by that date via the Azure Portal if they wish to avoid incurring charges when the subscription model activates.
How Hotpatching Works Under the Hood
The appeal of hotpatching lies in its ability to apply certain security updates by patching the running code in memory, eliminating the need for an immediate system restart. Microsoft promotes this for improving server availability and enabling quicker deployment of updates, noting the packages are often smaller. This faster patching can decrease the “window of vulnerability” – the time between a vulnerability disclosure and its remediation.
The technology itself has seen use within Microsoft; the company shared how its Xbox division benefited from hotpatching on Windows Server Azure Edition to streamline update processes. However, it’s not a complete elimination of restarts. A planned cadence involves four mandatory reboot months per year – January, April, July, and October – when full baseline cumulative updates are installed.
The goal is to deliver up to eight hotpatches in the intervening months, though Microsoft notes that critical security issues might occasionally force a traditional, reboot-requiring update even outside the baseline schedule. Enabling the feature for an Arc-connected server involves configuration through the Azure Update Manager within the Azure Portal.
Context and Exclusions
This subscription model specifically targets on-premises and multicloud deployments managed via Azure Arc. Hotpatching remains an included feature, without additional charge, for customers running Windows Server Datacenter: Azure Edition (both 2022 and 2025 versions) on virtual machines within the Azure cloud or on Azure Stack HCI platforms.
The underlying technology, including the quarterly reboot cycle and its current availability primarily on x64 hardware, mirrors the hotpatching feature also rolled out for specific, managed versions of Windows 11 Enterprise earlier in 2025.
When the capability was introduced for Arc-managed servers in preview, Hari Pulapaka, Microsoft’s General Manager of Windows Server, described it enthusiastically, stating: “This feature will be a game changer; simpler change control, shorter patch windows, easier orchestration… and you may finally get to see your family on the weekends.” Organizations now face a calculation weighing the subscription cost against the operational benefits of reduced planned downtime.
