How to Downgrade Windows Server Edition or License

When we analyzed the server licenses in use, we found that one of the servers had a much more expensive edition of Windows Server Datacenter installed than the tasks running on the server required (no Hyper-V virtualization, S2D, Azure Stack, Storage Replica, etc.). It was considered to change (downgrade) the edition of the installed Windows Server 2019 Datacenter to Standard to save on more expensive licenses. We did not consider a clean reinstall of Windows Server because the server already has a number of roles configured and additional software installed that is strictly licensed to the operating system and hardware.

Check Windows Server Edition

You can use the Control Panel to check which edition of Windows Server is installed on the host. Navigate to Control Panel –> System and Security -> System (or run the command: control /name Microsoft.System).

In this example, Windows Server 2019 Datacenter is installed on the host.

You can also view the version and edition of Windows from the command line:

systeminfo | findstr /B /C:"OS Name" /B /C:"OS Version"

or

wmic os get Caption, Version, BuildNumber, OSArchitecture

Or with PowerShell:

Get-WindowsEdition –Online

Get-ComputerInfo | select WindowsProductName, WindowsVersion, OsHardwareAbstractionLayer

The ServerDatacenter edition is installed on the host in this example.

You can use the Get-ADComputers cmdlet to get the edition of all the Windows Server hosts in an Active Directory domain:

Get-ADComputer -Filter {(Enabled -eq $True) -and (OperatingSystem -Like '*Windows Server*')} -Property * | Select-Object Name,OperatingSystem,OperatingSystemVersion

How to Downgrade Windows Server Datacenter to Windows Server Standard

Previously, we discussed upgrading a Windows Server edition from lower to higher using DISM (see the post How to convert Windows Server Evaluation to Full). You can also do the reverse procedure by downgrading from Datacenter edition to Standard, keeping all your current settings, installed roles, and applications.

Before performing a downgrade, we strongly recommend that you create a full image backup of your operating system (at least using Windows Server Backup).

You should also be careful if you are downgrading a Windows server with the ADDS domain controller role installed. It is recommended that you transfer FSMO roles from the Windows Server host (it is assumed that you have at least one additional domain controller) and demote it to a domain member server before downgrading. Back up your Domain Controller so that you can restore the DC from a backup in the event of a problem.

1. On a host running Windows Server 2019 Datacenter, start Registry Editor and navigate to the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion;
2. Check the values of the following REG_SZ parameters: EditionID = ServerDatacenter, ProductName = Windows Server 2019 Datacenter, CompositionEditionID=ServerDatacenter;
   The CompositionEditionID setting is present in the registry for Windows Server 2019 and Windows Server 2022. This registry parameter is missing in Windows Server 2016 and doesn’t need to be created manually.
    
3. Change the values as follows: EditionID and CompositionEditionIDto ServerStandard, ProductName to Windows Server 2019 Standard;
   It should be noted that there is a fairly rare edition of Windows Server Essentials available. To downgrade to Essential Edition, you must specify EditionID = ServerSolution.
   ; 
4. Close the Registry Editor;
   Do not restart the server after changing the values of the specified registry keys, otherwise, they will automatically revert to the previous values and you will get an error when trying to perform a downgrade in the next step “Your Files and Settings cannot be kept because you try to install an other version as the currently used“.
5. Mount the Windows Server 2019 installation ISO image and run the setup wizard (setup.exe);
6. When you select the installation options in the Windows Server Setup window, select Upgrade and Windows Server 2019 Standard (Desktop Experience); 
7. Check the option Keep personal files and apps. If this option isn’t available and you get the message “You can’t keep Windows settings, personal files, and apps because your current version of Windows might be installed in a unsupported directory”, check the values of the ProgramFilesPath, ProgramFilesDir(x86), and ProgramW6432Dir registry parameters under the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion registry key);
8. Click the Confirm button for each item found. In my case, the first item said that a Windows Server upgrade is not recommended, and it was better to clean install the OS, and the second one said that PnP and RemoteFX USB device redirection was disabled by default in this Windows version;
9. Start the Windows Server offline upgrade process. Wait for it to finish, and after a few restarts, check that Windows 2019 Standard Edition is now running on the host.

This downgrade method works for all supported versions of Windows Server (2012R2/2016/2019/2022).

Downgrade Rights: Windows Server 2022 to 2019/2016

Microsoft license agreements allow you to use earlier versions of Windows Server if you have a license for a newer version of the product (downgrade rights). For example, if you have the required commercial licenses for Windows Server 2022, you can run Windows Server 2019 and 2016.

To activate a previous version of Windows Server through a downgrade, you need to get a valid product key from your Volume Licensing Service Center (VLSC) account. If you do not have such a key, you can contact Microsoft support to generate a product key under the downgrade right.

It is not possible to perform an in-place downgrade of an already installed Windows operating system version. This means that if you have Windows Server 2022 installed but need Windows Server 2016 for legacy compatibility, you will not be able to downgrade your deployed operating system version. You will need to perform a fresh installation of Windows Server 2016 and activate it with the appropriate product key.