Microsoft is set to introduce hot patching for Windows Server, allowing users to install security updates without needing to reboot their systems. This feature, previously available only through Microsoft’s Azure cloud platform, will soon be offered in non-cloud versions of Windows Server. Though currently free in its preview phase, there will be a subscription fee of $1.50 per CPU core once it becomes generally available on July 1, 2025.
Hot patching enables the modification of the code of active processes in memory, which eliminates the need to restart them for security updates. The feature has been a part of the Windows Server Datacenter edition for years and has already proven helpful in reducing maintenance windows significantly. However, users will still need to perform full operating system updates four times a year, which will require a reboot.
Organizations can begin testing hot patching today via Azure Arc. Microsoft advises users to opt out before June 30 if they wish to avoid being billed for the service once it transitions to a paid model.
In addition to hot patching, Microsoft highlights that other updates, such as non-security fixes and driver updates, can also be applied without requiring a restart, thereby reducing system downtime.
While alternatives to in-memory patching exist, such as the 0patch initiative, Microsoft’s official solution is expected to offer superior management options for businesses heavily integrated into the Microsoft ecosystem.