Hotpatching

Hotpatching is a way of installing updates that doesn’t require a reboot after installation. Hotpatch for Windows Server has been available for the Azure Edition of Windows Server Datacenter for some time, and Microsoft announced in July 2025 that it was generally available for Windows Server 2025 as a subscription service from July 16, 2025.

Servers need to be connected to Azure Arc, and at that time the service cost $1.50 per CPU core per month. There are some useful screenshots in this GA announcement article showing the experience for enrolling in Hotpatch.

However, on May 19, 2026 Microsoft announced that Hotpatch would be available at no additional cost for Windows Server 2025 and that costs had stopped on May 15, 2026 for all servers currently enrolled in Hotpatch.