Security updates are a fundamental aspect of maintaining system integrity, and every security administrator understands the urgency of applying these updates swiftly to minimize risk. Traditionally, however, the process has been accompanied by a significant drawback: the necessity for Windows to reboot in order to implement these updates. This reboot requirement often leads to interruptions in productivity and downtime for users.
At Microsoft Digital, the internal IT organization of Microsoft, a transformative solution has emerged: Windows Hotpatch. This innovative approach allows for the delivery of critical Windows updates without the need for a reboot, fundamentally changing the dynamics of compliance, downtime, and user satisfaction.
“Hotpatch is helping Microsoft reach compliance faster than ever—no reboots, no delays, secure systems at scale, and a seamless experience that keeps users more productive,” explains Harshitha Digumarthi, a senior program manager within Microsoft Digital. “The risk exposure window is reduced drastically, making our environment safer and more resilient.”
Hotpatch operates by installing updates while the system remains active, eliminating the need for a reboot. This capability allows for quicker patching, enhanced compliance, and improved user experience. The impact is not limited to Microsoft; enterprise customers are already deploying Hotpatch across millions of devices, signaling a shift in organizational attitudes toward patching and update timelines.
Increasing productivity and security with Hotpatch
Hotpatch is a servicing technology that facilitates the delivery of cumulative security updates—typically released on Patch Tuesday—without requiring a system reboot. Rather than replacing binaries on disk and necessitating a restart, Hotpatch modifies in-memory code while the system is operational. This means updates take effect immediately, without any downtime or disruption to users.
Designed with efficiency in mind, Hotpatch payloads are intentionally small, leading to faster downloads and installations with minimal impact on system performance. CPU usage remains low, ensuring that updates run seamlessly in the background.
“The experience is so seamless you don’t even know what happened,” says Nevine Geissa, a partner group program manager within the Windows product team. “There are no process restarts, no logging out, no performance impact. Everything just works as if nothing has happened.”
To ensure the reliability of Hotpatch updates, they undergo the same rigorous validation processes as standard security updates. “Hotpatch updates go through the exact same validation and rigor that a standard security update goes through. There is no compromise on quality whatsoever,” asserts Geissa.
Even in the event of zero-day vulnerabilities, Hotpatch can deliver out-of-band updates to enrolled devices without requiring a reboot. This technology is available for Windows 11 version 24H2 or later, Windows 365, Azure Virtual Desktop, and Windows Server 2022/2025 Azure Edition, contingent upon appropriate licensing.
Hotpatch has evolved significantly over the years, initially developed for internal server capabilities in Azure and later expanded to Windows Server 2022 customers. “The tooling and OS support have matured such that now we can offer Hotpatch to AMD64 and Arm64 client machines too,” explains Nikita Deshpande, a senior customer experience program manager within the Windows Servicing and Delivery product team.
Hotpatch integrates seamlessly with Autopatch, a cloud-based service that automates the update process for Windows devices. Designed for enterprise environments and powered by Microsoft Intune, Autopatch reduces the manual effort required by IT administrators, allowing them to set up rings, monitor compliance, and roll out updates with ease.
Implementing Windows Hotpatch internally at Microsoft
The implementation of Hotpatch within Microsoft Digital has been a collaborative journey, beginning with the development and deployment of the feature and establishing trust among customers. The process started years ago in Azure with virtual machines and has since expanded to Windows 11 clients, scaling rapidly through deep collaboration between teams.
“We worked closely with the product team to ensure admins had the right metrics to measure success,” Digumarthi notes. “It’s not just about implementation—it’s about knowing it worked.”
Early adopter programs and insider rings provided valuable feedback, refining the experience and improving reporting to ensure a smooth rollout. Currently, Microsoft Digital is on track to scale Hotpatch to 450,000 devices within the next four months.
Achieving security without compromising on productivity
Hotpatching is redefining the approach to security within organizations. “With Hotpatch, we’re seeing 81% of Microsoft’s enrolled devices become compliant within 24 hours of Patch Tuesday and 90% within five days,” Digumarthi states. Previously, achieving 95% compliance could take up to nine months, exposing systems to risk for an extended period.
Now, with Hotpatch, that timeline has been reduced to less than three weeks. “We’re closing the gap from vulnerability discovery to patch deployment—without disrupting users,” Digumarthi adds.
Since its general availability in April, Hotpatch has already scaled to over 4 million devices globally, demonstrating significant trust and momentum within the market. This growth not only reflects the value of the technology but also highlights a shift in how organizations manage updates, allowing security teams to achieve compliance without friction.
Improving the user experience
Hotpatching enhances not only security but also the overall user experience. For end users, updates occur invisibly in the background, free from pop-ups, restarts, or performance hits. “It’s so seamless,” Geissa emphasizes. “There’s no bubble. No prompt. It just works.”
Users may occasionally see a green banner indicating a successful hotpatch, but the process remains largely unobtrusive. “It’s really helpful as an end user—I feel more secure,” shares Senthil Selvaraj, a principal group product manager at Microsoft Digital. “I don’t need to keep checking and making sure my device is up to date. It just is.”
Hotpatching not only protects individual devices but also supports the health of dependent applications and services, fostering an environment where everything functions reliably. For IT administrators, Intune reporting provides visibility into device readiness and compliance, minimizing the need for manual checks and reducing help desk calls.
Looking forward
The journey of Hotpatching is just beginning. At Microsoft Digital, plans are in place to expand from 100,000 to 450,000 devices in the coming months, while external adoption continues to accelerate. The product team is focused on enhancing compliance visibility, offering deeper insights into patch status and readiness, and simplifying the adoption process for customers.
With ongoing improvements to documentation and reporting, the vision remains clear: to secure every device without disruption, ensuring that organizations can maintain productivity while safeguarding their systems.
Key takeaways
- Check your eligibility and prerequisites. Understand your eligibility and set up the prerequisites in your environment to be hotpatch-capable.
- Monitor devices and report compliance. Use Intune and other reporting tools to track device readiness, update status, and compliance, even for unmanaged environments.
- Communicate the benefits to users. Inform users that hotpatching maintains their ability to reboot while enhancing device security with minimal disruption.
- Deliver a seamless update experience. Emphasize the uninterrupted, restart-free, and performance-neutral nature of updates for users.
For those interested in implementing Windows Hotpatch updates, further information is available to guide the process.
