Hotpatching prevents downtime by deploying regular patches without requiring a reboot. This method was originally slated to be discontinued with Windows Server 2022. However, it turns out that this user-friendly feature will still be available for Windows Server 2022 Datacenter: Azure Edition.
The Register discovered Redmond’s change of mind based on an updated Windows Release Health dashboard. Although the support period is nearing its end with October 31, 2026 still being the deadline, hotpatching will remain possible for the Azure Edition in 2027. Extended support is available through 2031.
Hotpatching is more than just convenient
The process of hotpatching revolves around not having to restart a running machine. In the case of devices running the Windows Server OS, it’s quite possible that the processes running on them are continuous and critical in nature. Administrators therefore sometimes choose not to restart their systems for patches, even though every installed patch is, in principle, an improvement to an organization’s security level.
Hotpatching, which is also available on enterprise Linux distributions such as Ubuntu LTS, RHEL, and derivative operating systems, is now available on Windows Server 2025 as well. Recently, this feature became free for the on-premises edition via Azure Arc. It’s no coincidence that Server 2025 is also the version of Microsoft’s own operating system that the company recommends upgrading to from Server 2022. The fact that this is no longer a paid option is a good thing. In our view, basic security features like this should never be behind a paywall.
No friction, but complex
Regardless of the OS version, hotpatching is never a permanent solution on Windows. Larger cumulative updates are released once a quarter and do require a reboot. Rebootless patching—where the kernel can be updated without downtime—is theoretically possible on Linux.
In any case, the process is a complex juggling act within system memory (RAM). To keep the OS running continuously, the RAM cannot be completely overwritten; therefore, hotpatching implementations must modify only the RAM data affected by the patch. This process results in a seamless update without downtime, but as is always the case with RAM-related matters: accidents can happen. If corruption occurs, a system can still crash, so hotpatching is a major responsibility for Microsoft and Linux vendors.