Many Windows Server installations start from the free evaluation ISO, and later the owner buys a product key and finds it will not activate. That is expected: an evaluation installation has to be converted to the full edition first. This guide shows how to check your edition, convert it with DISM, and activate it, for Windows Server 2016, 2019, 2022 and 2025.
How do you know if Windows Server is an evaluation version?
You can tell that Windows Server is an evaluation version by running DISM /online /Get-CurrentEdition in an elevated Command Prompt, which shows an edition name containing Eval, such as ServerStandardEval, or by running slmgr.vbs /dlv and looking for EVAL in the output; unactivated evaluations also show the remaining time on the desktop.
Microsoft's Windows Server conversion guide documents both checks. Evaluation media from the Microsoft Evaluation Center installs a time-limited edition, and Microsoft's Evaluation Center pages state that the evaluation expires after 180 days.
Cause and effect: an evaluation edition only accepts its own type of licence, so typing a retail Standard key into Settings or running slmgr /ipk on it fails or produces an error. The edition itself has to change first, and DISM is the tool that does that.
What do you need before converting Windows Server Evaluation?
Before converting, you need a valid product key for the same or a permitted target edition, an elevated Command Prompt or PowerShell session, a recent backup or snapshot, time for a restart, and confirmation that the server is not an Active Directory domain controller, because Microsoft does not support converting evaluation domain controllers.
- The right key: a Standard key for ServerStandard or a Datacenter key for ServerDatacenter, for the same Windows Server version.
- The same installation option: since Windows Server 2016, a Desktop Experience evaluation cannot be converted to a Server Core retail version.
- A matching target: an evaluation Datacenter installation can be converted to retail Datacenter only, not to Standard.
- A maintenance window: the conversion needs a restart, and in our experience it can take a while on slower disks.
Licences: Windows Server 2025 Standard, Windows Server 2022 Standard or 2019 Standard, with other editions in our Windows Server collection.
How do you convert Windows Server Evaluation to Standard or Datacenter?
To convert Windows Server Evaluation to a full version, open an elevated Command Prompt, run DISM /online /Get-TargetEditions to confirm the target is listed, then run DISM /online /Set-Edition:ServerStandard (or ServerDatacenter) /ProductKey: followed by your key and /AcceptEula, and restart the server when prompted to finish the conversion.
- Open Command Prompt as administrator.
- Check the current edition:
DISM /online /Get-CurrentEdition - List valid targets:
DISM /online /Get-TargetEditions - Optionally save the licence terms:
DISM /online /Set-Edition:ServerStandard /GetEula:C:\license.rtf - Convert, using your own key:
DISM /online /Set-Edition:ServerStandard /ProductKey:XXXXX-XXXXX-XXXXX-XXXXX-XXXXX /AcceptEula - Restart when DISM asks, and allow the restarts to complete.
Use ServerDatacenter in place of ServerStandard for a Datacenter key. If the edition you want does not appear in the /Get-TargetEditions list, Microsoft's guidance is to do a fresh install of the retail version instead.
What we commonly see: DISM reporting an invalid key because a Datacenter key was used with ServerStandard, or the other way round. Check the edition named in your order email and match it exactly.
How do you activate Windows Server after converting?
After the conversion and restart, activate Windows Server by opening an elevated Command Prompt and running slmgr.vbs /ato to activate online with the key you supplied to DISM, then confirm with slmgr.vbs /dli that the licence status reads Licensed and the description no longer mentions an evaluation channel.
- Run
DISM /online /Get-CurrentEditionand confirm the edition no longer ends in Eval. - Run
slmgr.vbs /atoto activate online. - Run
slmgr.vbs /dliand check the licence status.
On Desktop Experience you can also check the activation status in Settings. If activation fails with an edition-mismatch error, our 0xC004F050 troubleshooting guide explains the cause.
Advanced nuance: once the server is a full retail installation, Microsoft allows conversion between retail, volume and OEM licence channels at any time with slmgr.vbs /ipk, keeping the same edition. Microsoft's slmgr.vbs options reference lists each switch.
Can you convert an evaluation domain controller?
No, Microsoft states you cannot convert a domain controller running an evaluation version to a retail version; instead, install a new domain controller on a server running the retail edition, move any FSMO roles from the evaluation domain controller to it, then remove Active Directory Domain Services from the evaluation server before converting or retiring it.
- Build a new server from retail or volume media, or convert a non-DC evaluation server first.
- Promote it to a domain controller and let replication finish.
- Transfer the FSMO roles to the new domain controller.
- Demote the evaluation server by removing AD DS, then convert it with DISM or decommission it.
Our domain controller migration guide covers promotion, FSMO transfer and demotion in detail.
Advanced nuance: in a domain with a single domain controller, adding a second, licensed domain controller first also gives you redundancy. Keeping two domain controllers is a sensible design in its own right, so the conversion workaround often improves resilience as well.
What happens if the Windows Server evaluation period runs out?
When an evaluation runs out, Windows Server is no longer correctly licensed and, according to archived Microsoft TechNet guidance, starts shutting down about every hour, so the safe approach is to convert and activate before the 180-day period ends; Microsoft's Evaluation Center also requires evaluations to be activated online within the first 10 days, or they shut down automatically.
Converting with DISM keeps installed roles, applications and data, so there is no need to reinstall a working server. The conversion changes the edition and licence, not the configuration.
Cause and effect: periodic shutdowns interrupt every service on the server at once, from file shares to line-of-business databases, and an unexpected restart in the middle of a write can leave applications needing repair. Converting before the deadline avoids that disruption entirely.
What we commonly see: evaluation servers that were built as a quick test and quietly became production. Check every server you built from Evaluation Center media with DISM /online /Get-CurrentEdition, and record the result in your asset list.
Avoid relying on repeated resets of the evaluation timer for a server doing real work. An evaluation licence is for testing; production use needs a purchased licence and, for Standard and Datacenter, Windows Server CALs for the users or devices that connect, as covered in our CALs guide.
Frequently asked questions
Does converting from evaluation delete my data or roles?
No. DISM /Set-Edition changes the edition of the running installation and keeps installed roles, applications, settings and data. It does need a restart, so schedule a short maintenance window and take a backup or virtual machine snapshot first, which is good practice before any change to a server.
Can I convert Datacenter Evaluation to Standard?
No. Microsoft states that an evaluation Datacenter installation can only be converted to retail Datacenter, not to retail Standard. If you bought a Standard licence for a server installed from Datacenter evaluation media, perform a clean install of Standard or convert a Standard evaluation instead.
Does this work on Windows Server 2025?
Yes. Microsoft's conversion documentation applies to Windows Server 2025, 2022, 2019 and 2016, using the same DISM /online /Get-TargetEditions and /Set-Edition commands. Use a product key for the same version and edition, and confirm the target edition appears in the list before running the conversion.
How do I convert Windows Server Essentials Evaluation?
Microsoft documents a different method for Windows Server Essentials: run slmgr.vbs /ipk followed by your licence key in an elevated Command Prompt, instead of using DISM /Set-Edition. Then activate with slmgr.vbs /ato and check the result with slmgr.vbs /dli. If the key is rejected, confirm it is an Essentials key for the same Windows Server version.
Why does DISM say the product key is not valid?
The most common cause is a key for a different edition or version than the /Set-Edition target, such as a Datacenter key with ServerStandard or a 2019 key on 2022. Check the edition in your order email, confirm the target appears in /Get-TargetEditions, and contact support@licencehouse.com if it still fails.