Tired of all the restarts? Get hotpatching for Windows Server

Hotpatching for Windows Server 2025, made available in preview in 2024, will become generally available as a subscription service on July 1st, 2025. One of the key updates in the latest release of Windows Server 2025 is the addition of hybrid and multicloud capabilities, aligned with Azure’s adaptive cloud approach. With hotpatching, we are taking what was previously an Azure-only capability and now making it available to Windows Server machines outside of Azure through Azure Arc.

We encourage you to try hotpatching now while it’s still free of charge in preview, before subscription pricing starts this July. Read on to learn more.

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 the in-memory code of running processes without the need to restart the process.

Some of the benefits of hotpatching include the following:

• Higher availability with fewer reboots.
• 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 can decrease the “window of vulnerability” which can result if an administrator might normally delay an update and restart after a Windows security update is released.

Hotpatching is available at no charge to preview now, but starting in July with the subscription launch, hotpatching for Windows Server 2025 will be offered at 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: 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 on or before June 30 if you wish to end your preview and not subscribe to the service. Otherwise, your subscription will start automatically in July.

If you’re running on Azure IaaS, Azure Local, or Azure Stack 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 price 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 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 will be billed on a monthly basis, 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 attend our Windows Server Summit virtual event on April 29-30 and on-demand. We encourage you to try this new time-saving feature during this preview 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 chang

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

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