Rebootless updates come to Windows 11 Enterprise and 365 for security updates

"Hotpatch updates are scoped and provide a complete set of OS security patches. No additional features are included," Microsoft explains. "They are unique in that they take effect immediately upon installation without requiring you to restart your device, helping to ensure focused, rapid protection."

Hotpatch updates have been available in the Windows Server 2022 Datacenter: Azure Edition since February 2022 and now in Windows Server 2025. They are proving to be more than a quality-of-life update as they reduce the system downtime for every restart needed for the security patch.

Hotpatching updates the in-memory code with the update, thus not requiring a system restart. Hotpatching also has other benefits, as mentioned by Microsoft:

Hotpatching is also incredibly useful for commercial workloads, given that security patches are regularly required, some more seriously than usual. This way, users no longer need to schedule an update for a critical patch and schedule a restart for servers and complex clusters using these operating systems. Microsoft also uses hotpatching for its clusters, such as the Xbox network.

We reported about Microsoft testing hotpatching internally a few months ago, where Microsoft wishes to roll this for 22H2 versions and for Arm64-based devices, whose rollout will bedelayed by a whole year.

There are limitations to hotpatching as it works only for security patches. This means Cumulative Updates, which roll out during the first month of every quarter, will need a restart. It should be noted that for Windows Server 2022 and 2025, hotpatching does not include non-security updates for Windows, .NET updates, and non-windows patches such as firmware, drivers, and software updates.- and likely to be the case with Windows 11 Enterprise and Windows 365.

Windows 11 Enterprise editions are part of the Windows Enterprise subscription, which comes in Enterprise E3, Enterprise E5, and Microsoft 365 Enterprise plans. Those who have subscribed to this plan will need a Windows 11 Pro license. Windows 11 Enterprise includes more features, such as Azure Virtual Desktop, Credential Guard, Direct Access, Universal Print, and others. Pro and Enterprise versions are made for business users but with specific purposes.

One might expect hotpatching to inevitably arrive for Windows Home and Pro editions, though hotpatching is more beneficial for systems with a more complex deployment. Restarting every system after an update is impractical for many situations, as it involves downtime.