Up to Version 2019 yes it’s free. You can download an ISO file from Microsoft, boot with it on your physical server and then setup Hyper-V as usual. As of Jan/2023 there is no free 2022 version. However you can download a windows 2022 evaluation ISO, install on a physical server the Core edition and add the Hyper-V as a feature using the following powershell command: Install-WindowsFeature -Name Hyper-V -IncludeManagementTools -Restart   Check this really interesting article: How to Install Hyper-V on Windows Server Core