Yes, you can install Windows Server 2022 Essentials as a VM on XCP-ng, but the issue is likely due to using a DELL ROK DVD. ROK media checks for DELL hardware during setup and won’t work properly in a virtual environment like XCP-ng. Instead, download the standard Microsoft ISO for Server 2022 Essentials and install that. If your DELL key doesn’t work or you need a new one, you can get a genuine key from Noxkeys.com for around $20 worked perfectly for me. Activation was smooth after that.