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Hotpatching in Windows Server 2025

Trouble-Free

Article from ADMIN 90/2025

By Thomas Joos

Hotpatching technology on Windows Server 2025 reduces downtime and maintenance windows, but it comes at a price in the truest sense of the word. We look at the technical details of hotpatching, show how to get started, and weigh the pros and cons.

Hotpatching directly modifies the code of processes running in RAM, eliminating the need for a restart. The key advantage is reduction of downtime, as servers remain operational and security updates are made without delay. Not all updates support this technology, though, and hotpatching will probably be limited to regular patch day updates in the future. Because not all updates support hotpatching, rebooting is still necessary, which certainly puts the benefits into perspective. In this article, you'll also learn about more limitations.

Microsoft Azure Required

On Windows Server 2022, you need the Datacenter: Azure Edition license, which must be running in Azure or Azure Stack hyperconverged infrastructure (HCI), to use hotpatching. Although hotpatching will also be available in local data centers in the Standard and Datacenter editions in the future, you still need an Azure connection.

To use hotpatching, you must first enable virtualization-based security (VBS) on Windows Server 2025 in the Security | Secured-core section of the Windows Admin Center (Figure 1). VBS uses Hyper-V virtualization technology to move security-critical processes to an isolated environment. VBS isolates particularly sensitive data and processes from the regular operating system environment, which greatly limits the possibilities for attack.

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