How does hotpatching work?

Hotpatching is a new way to install updates in Windows Server 2025 that does not require a reboot after installation, by patching in-memory code of running processes without the need to restart the process, the application, or operating system.

Some of the benefits of hotpatching include the following:

• Greater uptime with fewer reboots, instead of rebooting monthly (12 times a year) rebooting is reduced to quarterly (4 times a year).
• Faster deployment of updates as the packages are smaller, install faster, and have easier patch orchestration with Azure Update Manager (optional).
• Hotpatch packages install without the need to schedule a reboot, so they can happen sooner. This decreases the “window of vulnerability” which can result if an administrator might normally delay an update and restart after a Windows security update is released.

Azure Arc-enabled Hotpatching for Windows Server 2025 is available for a subscription of $1.50 USD per CPU core per month. 

With hotpatching, you will still need to restart your Windows Servers about four times yearly for baseline updates, but hotpatching can save significant time and ease the inconvenience of a traditional “patch Tuesday.” 

Hotpatching for Windows Server Datacenter: Azure Edition has been available for years. In fact, our own Xbox team has used it to reduce processes that used to take the team weeks down to just a couple of days. With Windows Server 2025, we have been able to deliver these efficiencies to on-premises and non-Azure servers through connection with Azure Arc.

What are the requirements?

To use hotpatching outside of Azure such as, on-premises or in multicloud environments, you must be using Windows Server 2025 Standard or Datacenter, and your server must be connected to Azure Arc. You will also need to subscribe to the Hotpatch service.

Important reminder: If you are currently using Windows Server 2025 and opted in to try the hotpatching service through Azure Arc in preview, you will need to disenroll if you wish to end your preview and not subscribe to the service. Otherwise, your subscription starts automatically in July 2025.

If you’re running on Azure IaaS, or Azure Local you can still use hotpatching as part of functionality of Windows Server Datacenter: Azure Edition. This feature is included both with Windows Server 2022 Datacenter: Azure Edition and Windows Server 2025 Datacenter: Azure Edition. There are no new requirements in this case, i.e. you don’t need to Arc-enable those machines, and there’s no additional cost for it. 

How do I enable hotpatching?

First, if your server is not yet connected to Azure Arc, you can do so by following these steps. Azure Arc is available at no extra cost and lets you manage physical servers, and virtual machines hosted outside of Azure, on your corporate network, or other cloud providers. In addition to hotpatching, there are several paid Azure services you can access through Azure Arc, including Microsoft Defender for Cloud, Azure Monitor, and many others. For full details, refer to this documentation.

Once you are connected with Azure Arc, you will sign into the Azure Portal, go to Azure Update Manager, select your Azure Arc-enabled server, and select the hotpatching option as outlined in this documentation.

You can also manage your subscription to hotpatching through the Azure Portal as well.

What is the difference between hotpatches and traditional patches/LCUs? 

At Microsoft we have traditionally shipped patches known as Latest Cumulative Updates (LCU). An LCU can have a few different types of fixes in its payload such as: 

1. Security fixes 
2. Bug fixes that are not security fixes 
3. New feature payload 

In contrast, a hotpatch only includes security fixes which makes the patch smaller and scoped to security only. We still need to deliver on #2 and #3 above, so we synchronize these payloads once a quarter in the Hotpatching schedule. 

What is the hotpatching schedule?

The hotpatch service provides up to eight hotpatches in a year. It follows a three-month cycle with the first month as a baseline month (monthly cumulative update) followed by two months of hotpatches. During baseline months the machines will need a reboot. The four planned baseline months are January, April, July and October.

On rare occasions, for security reasons we may have to ship a non-hotpatch update during a hotpatch month which will also need a reboot. But the goal will be to provide up to eight hotpatches in a year. 

The Windows Server hotpatching subscription is billed monthly, so your cost will be consistent throughout the year in both hotpatch and non-hotpatch months. 

Where to learn more about Windows Server

In addition to the documentation above, please check out our blog posts on Tech Community and watch the on-demand videos from the 2025 Windows Server Summit virtual event. We encourage you to try this time-saving feature and start discovering all the time you’ll save! 

And don’t forget…

As you may have heard at Ignite, hotpatching is also available for Windows 11 Enterprise. Learn more about eligibility and hotpatching for Windows clients here.

*Prices are in US dollars and are subject to change

The post Tired of all the restarts? Get hotpatching for Windows Server appeared first on Microsoft Windows Server Blog.

Stay ahead of the curve and learn about the latest innovations and best practices in the world of Windows Server. Session recordings from the Windows Server Summit 2024 virtual event sponsored by Intel^® are available on-demand.

Designed for experienced IT professionals and IT leaders, the event will help deepen knowledge and skills of Windows Server and managing Windows Server workloads in hybrid cloud environments. The event includes talks by Microsoft product engineers, Intel® experts, and Microsoft Most Valuable Professionals (MVPs) sharing insights and tips to get the most out of Windows Server. You won’t want to miss the sneak peek of exciting features and enhancements coming in Windows Server 2025, the next major release of Microsoft’s server operating system!

Windows Server Summit

Recorded presentations available on-demand

View sessions today

Windows Server Summit has been an annual virtual event for the past three years. This year we responded to feedback on this popular event by including more demos and deeper technical content. All sessions are presented by Microsoft engineering teams and technical leaders from Intel® as well as our highly skilled Microsoft MVPs. Here are some examples of our expert content:

Windows Server 2025 preview

Did you catch the Microsoft Ignite 2023 session with Jeff Woolsey and Elden Christensen in matching purple shirts? That was still early days—there is more to share! In his Windows Server Summit session, Elden will provide an overview of all the new features and improvements to expect in Windows Server 2025 when released in late 2024.

Did you know that while you are playing Xbox at home, the team supporting the backend services uses Hotpatch? Find out how they do it in our session with Vishal Baja and Viraj Desai from Windows engineering and Tim Dreyling from Xbox networking teams.

Is software defined networking (SDN) your thing? You won’t want to miss Cindy Wan, Anirban Paul, Kyle Bisnett, and Samuel Liu of the SDN team for their demo bash session—including how to use upcoming Azure Kubernetes Services (AKS) and network security enhancements.

Are you looking for ways to prepare for AI? Afia Boakye and Nicole Bourain from the core operating system (OS) virtualization team will dive into new features in the Windows Server and Azure Stack HCI covering GPU failover clustering and new GPU partitioning (GPU-P) for GPU virtualization.

Security and hardening Windows Server

What are your thoughts on NTLM? Join Ned Pyle as he walks you through the evolution of Windows Authentication with Windows Server 2025 updates to NTLM and Kerberos improvement.

Eric Woodruff, Security MVP, is sharing his expertise with sessions on taking steps to secure Windows Server Active Directory with the Security Compliance Toolkit and Center for Internet Security (CIS) Benchmarks as well as a session specific to protecting your server from management plane attacks.

Microsoft understands not every server is running the latest version of Windows Server. Still, keeping your servers secure is vital. Join Principal Product Managers Poornima Priyadarshini and Jason Leznek to learn how Azure Arc extends the Azure control plane to on-premises servers and take advantage of Extended Security Updates (ESUs) on a flexible monthly billing model with keyless activation.

Windows Server hybrid and cloud

Are you running Windows Server on-premises or at the edge? Learn how you can leverage Azure automation, PowerShell, run command, and many other Azure management solutions for your on-premises Windows Servers. Thomas Maurer, Senior Program Manager and Chief Evangelist Azure Hybrid, and Ryan Willis, Product Manager for Azure Arc, will share how to automate your on-premises Windows Server from the cloud using Azure Arc.

Upgrades and migrations

Want to understand the details of Windows Server upgrade and update processes? We have the core team responsible front and center to walk you through the “how” and “when” of updates—including the upgrade path from Windows Server 2018 to Windows Server 2025.

Gregor Reimling is a rare, dual category MVP in Azure and Security. He will share his best practices for a successful Azure migration starting with the Cloud Adoption Framework (CAF) and look at the Azure Migrate and Modernize program.

Windows Server best practices

Fady Azmy, Program Manager for Windows Server will share practical strategies and best practices for using containers to boost efficiency and simplify deployment while maximizing resource utilization for Windows Server applications.

Interested in host networking on the edge? Join Basel Kablawi, Product Manager for network data plane, and Anirban Paul, Principal Product Manager, as they share what’s new and exciting in networking for Windows Server, highlighting Network ATC, Network HUD, and Accelerated Networking.

Be sure to watch these and other great sessions from our expert speakers!

The post Check out Microsoft Windows Server Summit 2024 appeared first on Microsoft Windows Server Blog.

We’re excited to invite you to the fourth annual Windows Server Summit digital event, happening on December 6, 2022, at 9:00 AM Pacific Time. This has been a popular digital event among our Windows Server community, attracting thousands of IT managers, chief technical officers, systems administrators, cloud architects, and other IT professionals from organizations of all sizes. We know your time is precious, so here’s a quick preview of what’s in the event for you, and why you should join us:

More demos, fewer slides

Your feedback has been heard. In past events, you’ve expressed interest in seeing features in action, rather than just hearing us talk about them. In this event, you’ll experience clear, step-by-step walk-throughs of Windows Server 2022, Windows Admin Center, and Azure Arc as well as new products like Azure Automanage.

Focus on the practical, while looking ahead to what’s possible

In each of our sessions, we have tried to stay grounded in the practical challenges you need to manage today, like keeping your IT environment secure, giving your team better capabilities for working remotely, managing your IT estate, and determining what to do next with older technology, like Windows Server 2012 (reaching end of support October 10, 2023). In addition to these essential topics, we’re excited to offer a few sneak peeks at what is coming next and share with you ways to migrate and modernize to take advantage of Azure capabilities.

Hear from Microsoft experts and get your questions answered

Attendees of the December 6 event will have a chance to get their questions answered by Windows Server and Azure experts through live chat. You’ll hear from Roanne Sones, Corporate Vice President of Azure Edge and Platform on her vision for Windows Server and hybrid cloud. Of course, we have sessions led by familiar Microsoft personalities including Jeff Woolsey, Sonia Cuff, Rick Claus, Ned Pyle, Thomas Maurer, and the list goes on.

Learn more

If you want to learn with the Windows Server community, or just want more information about Windows Server 2022, Azure Kubernetes Service, Azure Arc, or cloud migration, please sign up for the Windows Server Summit to join us.

Windows Server Summit

Learn new opportunities to innovate and operate more efficiently.

Register now

The post Join us for Windows Server Summit 2022 appeared first on Microsoft Windows Server Blog.