Activation of Windows Server 2025 Standard virtual machine with HPE ROK Windows Key fails

[Spider5]

Hello, everyone
I have installed an HPE ProLiant DL345 Gen11 server as a Hyper-V host using the Windows Server 2025 STD ROK DVD from HPE. I was able to activate it successfully. I also have a Microsoft Windows Server 2025 (16-core) Standard Additional License for the server. I then want to install four virtual machines with Windows Server 2025 Standard. Since I couldn't find an ISO file as ROK at HPE, I downloaded Microsoft Windows Server 2025 Standard Evaluation as an ISO file and used it to install the virtual machines. When I try to activate them with dism /online /set-edition:ServerStandard /productkey:XXXXX-XXXXX-XXXXX-XXXXX-XXXXX /accepteula, I get error 1168. The key is probably not accepted. How can I activate the virtual machines? Or do I need an ISO file in the ROK version for the key to work?
I look forward to your help.
Best regards

[Spider5 · Accepted solution]

I found the solution in HPE documentation “Microsoft Windows Server OEM licensing from HPE”
https://www.hpe.com/psnow/doc/4aa4-3787enw
This can be found on page 23 in the chapter "Virtualization and OEM licensing" under point 61.
You have to set a manufacturer string (BiosLockString..) in the registry of the virtual machine.
After restarting, you can proceed with activation.