Transforming security and compliance at Microsoft with Windows Hotpatch

Security updates are essential, and every security admin knows that when it comes to applying these updates, faster is better to mitigate the risk. However, security updates have always come with a catch: Windows needs to reboot to apply them.

Reboots mean interrupted productivity and downtime for users.

For us at Microsoft Digital, Microsoft’s internal IT organization, Windows Hotpatch changes the equation.

It’s a new way to deliver critical Windows updates without rebooting. That means faster compliance, less downtime, and happier users.

We’re using it across Microsoft and it’s already transforming how we think about security and productivity.

“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. The risk exposure window is reduced drastically, making our environment safer and more resilient,” says Harshitha Digumarthi, a senior program manager within Microsoft Digital.

Hotpatch installs updates while the system is running—no reboot required. That means we can patch faster, stay compliant, and keep users happy.

And it’s not just us.

Microsoft enterprise customers are already scaling deployments to millions of devices. We’re seeing a shift in how organizations think about patching and how they can expedite the patch time. Hotpatch is here to help. It’s no longer a disruption, it’s just part of the flow.

Increasing productivity and security with Hotpatch

Hotpatch is a servicing technology that delivers cumulative security updates—released on Patch Tuesday, the second Tuesday of each month—without requiring a system reboot. Instead of replacing binaries on disk and restarting the system, Hotpatch modifies in-memory code while the system is running.

This means updates take effect immediately, with no downtime, no maintenance windows, and no disruption to users.

Hotpatch payloads are small by design. Smaller updates mean faster downloads, quicker installs, and minimal impact on performance. CPU usage stays low. No spikes. No slowdowns. Just updates that run in the background and finish silently.

“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. No glitch in the video playing or transaction dropping. Everything just works as if nothing has happened.”

Because hotpatch updates happen so painlessly in the background, IT administrators may want to understand how the process works and what validation steps are involved. That’s why we test hotpatch updates with the same rigorous standards we apply to all our 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. Your device is always as secure as your non-hotpatch device.”

Nevine Geissa, partner group program manager, Windows Servicing and Delivery

Even in cases of zero-day vulnerabilities, Hotpatch can deliver out-of-band updates to enrolled devices without requiring a reboot.

Hotpatch is available for Windows 11 version 24H2 or later, Windows 365, Azure Virtual Desktop, Windows Server 2022/2025 Azure Edition, and Azure Arc connected Windows Server 2025 Datacenter and Standard editions.

The technology has matured over years of internal development.

“Hotpatch updates go through the exact same validation and rigor that a standard security update goes through,” Geissa says. “There is no compromise on quality whatsoever. You will always be at the exact same level of security.”

Hotpatch has evolved and grown.

“It started as internal server capability in Azure and then expanded to our Windows Server 2022 customers,” says Nikita Deshpande, a senior customer experience program manager within the Windows Servicing and Delivery product team at Microsoft. “The tooling and OS support have matured such that now we can offer Hotpatch to AMD64 and Arm64 client machines now too.”

Hotpatch integrates seamlessly with Autopatch, a cloud-based service from Microsoft that automates the process of keeping Windows devices up to date. Designed for enterprise environments, and powered by Microsoft Intune, Autopatch manages updates for Windows, Microsoft 365 Apps for enterprise, Microsoft Edge, and Microsoft Teams, reducing the manual effort required by IT administrators.

Any new policy in our environment created with Autopatch automatically enables Hotpatch—if the device meets requirements. Admins can set up rings, monitor compliance, and roll out updates with just a few clicks.

“It’s the better together story,” Deshpande says. “Autopatch streamlines everything. Add Hotpatch, and it takes Windows Update to a whole new level.”

Implementing Windows Hotpatch internally at Microsoft

The implementation of Hotpatch at Microsoft Digital involved developing and deploying a feature, as well as establishing trust for customers.

The journey started years ago in Azure with virtual machines, then to Windows Server across physical and virtual instances. Now, it’s on Windows 11 clients and scaling fast, but getting here took deep collaboration.

Our team in Microsoft Digital partnered with the product team from the start. We were co-designers with experience in this space. We helped shape the rollout, validate the experience, and make sure Hotpatch was ready for enterprise scale.

Then we scaled. We expanded to 40,000, then 80,000, then 120,000 devices. We’re on track to reach 450,000 devices at Microsoft in the next four months.

We also wanted a great admin experience enabled for the product. The features help with smooth rollout and the visibility helps admins monitor rollouts and measure impact. We’re continually collaborating with the Windows product team to equip administrators with comprehensive insights and actionable recommendations with Hotpatch.

“We worked closely with the product team to make sure admins had the right metrics to measure the success,” Digumarthi says. “It’s not just about implementation—it’s about knowing it worked.”

We ran early adopter programs and insider rings to gather feedback from across Microsoft. That feedback loop helped refine the experience, improve reporting, and ensure the rollout was smooth.

Achieving security without compromising on productivity

Hotpatching is changing how we think about security.

“With Hotpatch, we’re seeing 81% of Microsoft’s enrolled devices become compliant within 24 hours of Patch Tuesday and 90% of enrolled devices are patched within five days.”

Harshitha Digumarthi, senior program manager, Microsoft Digital

Before, it took our team up to nine months to reach 95% compliance for security patching.

That’s nine months of exposure and nine months of risk.

With Hotpatch, we’re achieving 95% compliance in less than three weeks.

“With Hotpatch, we’re seeing 81% of Microsoft’s enrolled devices become compliant within 24 hours of Patch Tuesday, and 90% of enrolled devices are compliant within five days,” Digumarthi says.

That’s not just faster. It’s safer.

“We’re reducing the risk window,” Digumarthi says. “From vulnerability discovery to patch deployment, we’re closing the gap—without disrupting users.”

And it’s not just internal. Since general availability in April, Hotpatch has scaled to over 4.5 million devices globally. That growth shows trust and momentum.

It also shows value. Admins spend less time chasing updates. End users stay productive. And security teams get the compliance they need—without the friction.

“Hotpatching eliminates the trade-off between security and productivity,” Deshpande says. “You don’t have to choose anymore.”

Improving the user experience

Hotpatching doesn’t just improve security—it transforms the user experience.

For end users, it’s invisible.

Updates happen in the background.

No pop-ups. No restarts. No performance hits.

“It’s so seamless,” Geissa says. “There’s no bubble. No prompt. It just works.”

Even the first few times, users might see a green banner letting them know they’ve been hotpatched.

“It’s really helpful as an end user; I feel more secure. I don’t need to keep checking and making sure my device is up to date. It just is.”

Senthil Selvaraj, principal group product manager, Microsoft Digital

It’s subtle. It’s clean.

It’s so effective that it’s become a kind of badge among Microsoft insiders.

“It’s really helpful as an end user—I feel more secure,” says 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.”

That’s the magic.

Hotpatching doesn’t interrupt work—it protects it.

It helps other systems stay current too. When the OS is secure, dependent apps and services can update more reliably. That ripple effect improves the overall health of the device.

Admins also see the benefits. Intune reporting shows which devices are ready, which have updated, and which need attention. That visibility helps IT teams track compliance without chasing down machines or relying on manual checks.

For enterprises, it means fewer help desk calls. Fewer complaints. Fewer delays.

Looking forward

Hotpatching is just getting started.

At Microsoft Digital, we’re expanding from 100K to 450K devices in the next four months. That’s nearly every eligible device in our fleet.

Externally, adoption is accelerating. We’ve gone from zero to almost 4.5 million devices since private preview in November 2024. That includes Microsoft and customer fleets, and the number keeps growing.

But scale is just the beginning.

The product team is exploring ways to improve compliance visibility—giving admins deeper insights into patch status, readiness, and impact. That means better reporting, smarter dashboards, and tighter integration with compliance tools.

We’re also working to make adoption easier.

Documentation is improving, Intune reporting is evolving, and we’re building clearer guidance for customers to validate their environments, understand their risk posture, and deploy Hotpatch confidently.

The vision is simple: secure every device, without disruption.