Introduction

Microsoft has unveiled a groundbreaking feature in Windows 11 version 24H2: Hotpatching. This innovation allows security updates to be applied without necessitating a system reboot, marking a significant advancement in maintaining device security while minimizing user disruption.

Background on Hotpatching

Hotpatching is not a novel concept; it has been utilized in Windows Server environments since February 2022, particularly in Windows Server 2022 Datacenter: Azure Edition. The technology enables the application of security patches to the in-memory code of running processes, eliminating the need for a restart. By extending this capability to Windows 11 Enterprise, Microsoft aims to enhance productivity and security for enterprise users.

How Hotpatching Works

Hotpatching operates on a quarterly update cycle:

  1. Baseline Month (January, April, July, October):
  • Devices receive a comprehensive security update that includes the latest fixes, features, and enhancements.
  • A system restart is required to apply this update.
  1. Subsequent Two Months:
  • Devices receive hotpatch updates containing only security fixes.
  • These updates are applied immediately without requiring a restart.

This cycle reduces the number of required restarts from twelve to four per year, thereby enhancing user productivity and system uptime.

Technical Details and Requirements

To implement hotpatching, organizations must meet the following criteria:

  • Operating System:
    • Windows 11 Enterprise, version 24H2 (Build 26100.2033 or later).
  • Subscription:
    • Windows 11 Enterprise E3, E5, or F3.
    • Windows 11 Education A3 or A5.
    • Windows 365 Enterprise subscription.
  • Hardware:
    • Devices with x64 (AMD/Intel) CPUs.
    • Arm64 devices are currently in public preview and require additional configuration.
  • Management Tools:
    • Microsoft Intune for deploying hotpatch updates via a hotpatch-enabled Windows quality update policy.
  • Security Features:
    • Virtualization-based Security (VBS) must be enabled.

For Arm64 devices, administrators need to disable CHPE support by setting a specific registry key:

CODEBLOCK0

A system restart is necessary to apply this setting.

Implications and Impact

The introduction of hotpatching in Windows 11 Enterprise offers several benefits:

  • Immediate Protection:
    • Security updates take effect immediately upon installation, reducing exposure to vulnerabilities.
  • Minimized Disruptions:
    • Users can continue their work uninterrupted, as most security updates no longer require a system restart.
  • Operational Efficiency:
    • IT departments can streamline update deployment, reducing the complexity and downtime associated with traditional update processes.

Conclusion

Microsoft's implementation of hotpatching in Windows 11 version 24H2 represents a significant step forward in balancing robust security with user productivity. By reducing the need for system restarts, organizations can maintain a secure environment while minimizing operational disruptions.