Assumes you have a valid ESU license and Windows Server 2008 SP2 (x64 or x86).
In-place upgrades from Server 2008 are to 2016 or newer. You must:
If you are still running a server on Build 6003, it is now officially an unsupported and insecure Migration: Microsoft recommends migrating workloads to Azure Virtual Machines or upgrading to a modern version like Windows Server 2022 Windows Server 2025 Security Risk:
Build 6003 was a unique version of Windows Server 2008 Service Pack 2 (SP2). It was introduced by Microsoft to bypass internal limitations on version numbering. Why the change?