Microsoft wants to streamline the update process for Windows Server with “hot patches.” This allows servers to install updates without the need for a reboot.

Performing a Windows update requires a restart of your device, and Windows Server is no exception. Knowing that Microsoft releases a security update every month means that your servers will be down for at least a few minutes 12 times a year. By adding “hot patches” to Windows Server 2025, Microsoft wants to make sure that downtime is no longer an excuse for delaying updates.

With a hot patch, the operating system receives an update without the need for a restart. The entire update process then runs in the background, which is much less disruptive for users. Microsoft cites lower server load, faster installation of updates and simpler update orchestration as the main advantages.

Azure Arc

The concept of hot patching is not entirely new in Windows Server. Technically, this has been possible for several years, but only by running a virtual machine on Azure or Azure Stack HCI. Now hot patching is possible with just a few clicks via Azure Arc. The feature is available via the public preview of Windows Server 2025.

Be careful: The addition of hot patches doesn’t mean you’ll never have to reboot your servers again. But Microsoft says the number of mandatory reboots will drop from one per month to one per quarter, with “the rare possibility that reboots will be required in a nominal hotpatch month.” Of course, unexpected updates along the way can always require a reboot, such as to close a serious zero-day leak.

Hot patches also seem to be available for Windows 11 starting with the upcoming 24H2 update. Microsoft has been testing this in Windows since February, but has remained tight-lipped about the rollout of the feature. It is unclear whether all versions of Windows will receive the feature or, for example, only the business versions.