How to raise domain and forest functional levels required for the promotion of a Windows Server 2022 or 2025 domain controller By Mariette Knap Forest and Domain Functional Levels, DC promo For promoting a Windows Server 2025 domain controller, the minimum domain and forest functional levels required are Windows Server 2016. This means that all domain controllers in your environment must be running at least Windows Server 2016 functional levels to introduce a Windows Server 2025 domain controller. You cannot introduce a Windows Server 2025 DC into a domain running older functional levels like Windows Server 2012 or earlier. Windows Server Version Minimum Domain Functional Level (DFL) Minimum Forest Functional Level (FFL) New Features Introduced Windows Server 2022 Windows Server 2008 Windows Server 2008 No new functional levels; security improvements for hybrid environments. Windows Server 2025 (Preview) Windows Server 2016 Windows Server 2016 New 32K database page size, performance upgrades, and schema updates. Get your free tutorial Get your Technician Kit Free tutorial for registered users only Register a new free account within 30 seconds and get access to this tutorial and many other on this site Register a free account Easy migration kits Migration kit for migrating from one source (for example Windows Server 2012) to a new Windows Server environment built on the latest technology. This kit is ideal if you want to perform the migration of your old server yourself. The kit contains everything to ultimately run your infrastructure on more modern operating systems like Windows Server 2016, 2019, 2022 or 2025. Success guaranteed! Get your easy migration kit All our migration kits and IT Pro Collections are backed with awesome support. In our store, you can choose to purchase support as part of your initial purchase or you can get ad hoc support by creating a support ticket here. Don't want to do it yourself? Migration support is also available through consulting service, contact us.