Downgrading Windows Server DataCenter to Standard Edition

Microsoft does not officially support downgrading Windows Server DataCenter to Standard Edition as a direct method. However, a workaround involves modifying the registry and running the official Standard Edition ISO. This method can facilitate a stable transition while preserving system functionality.

Before proceeding, it is highly recommended to back up all critical data and configurations to prevent any potential data loss. Do not apply this method on domain controllers (DCs) unless you have a verified backup.

Registry Modifications:
Navigate to:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion

Modify the following values:

EditionID = ServerStandard
CompositionEditionID = ServerStandard
ProductName = Windows Server 20XX Standard (Replace with 2019, 2022, or 2025 based on your version)
After making these changes, proceed with running the Standard Edition ISO to complete the downgrade process.