If you’re anything like me, you’ve found Microsoft’s path to licensing to be a labyrinth of confusion. You may want to upgrade a fleet of evaulation servers in your dev environment to production servers, but dread the thought of rebuilding everything from scratch because Windows Eval won’t accept your Volume License Keys.

Recently I have discovered a way to do these upgrades without requiring a reinstall by using DISM (Deployment Image Servicing and Management). This workflow has saved me countless hours, and I hope it will be helpful to others who are navigating the same terrain.

This process is specific for people trying to license Windows Server Eval with a volume license key from their KMS. If you are trying to upgrade an eval server with a retail license key you do not need to change the license channel and can skip to activating the server.

What is DISM?

DISM is a powerful command-line tool built into Windows that’s used to service and prepare Windows images, including those used for Windows PE, Windows Recovery Environment (Windows RE), and Windows Setup.

How to Upgrade from Eval to Standard

Here’s the process in a nutshell, using PowerShell:

  1. Change the license channel: Windows will not accept your volume license key as valid if it is currently licensed as a retail evaluation copy. Here is the Windows GLVK website. Choose the license that corresponds with the keys you will ultimately use. We’ll use Server 2022 Standard:
dism /online /set-edition:ServerStandard /productkey:VDYBN-27WPP-V4HQT-9VMD4-VMK7H /accepteula

This command sets the online Windows image to the Server Standard 2022 edition using the corresponding generic KMS key. The /accepteula parameter is used to automatically accept the end-user license agreement.

  1. Reboot the server: Once you run the above command, you should reboot your server.

  2. Activate the server with the purchased key: After the reboot, you will need to proceed with the following commands to activate the Server with your purchased key:

slmgr /upk
slmgr /ato

The slmgr /upk command uninstalls the current product key. The slmgr /ipk command installs the new product key, replacing ‘XXXXX-XXXXX-XXXXX-XXXXX-XXXXX’ with your actual product key. Finally, the slmgr /ato command activates Windows.

Extending the Evaluation Period

If you’re not ready to upgrade yet, DISM provides a way to extend the evaluation period of your server. The command slmgr /rearm resets the licensing status of your machine and extends the evaluation period.

slmgr /rearm

Remember, you can use this command up to three times to extend the evaluation period to a total of 120 days. If you’re trying to maximize the trial period you could make a script to execute this command on a 120 day timer.

In Conclusion

By using DISM, you can easily manage your Windows licenses without having to rebuild your servers from scratch. I hope this guide serves as a useful resource for anyone who finds themselves in a similar licensing pickle.