Buy windows, like a license? Try URCDkeys or whokeys. There is a cool tool to download any windows versions: www.heidoc.net/joomla/technology-science/microsoft/67-microsoft-windows-and-office-iso-download-tool Then just purchase a license to enter the key and activate after installing.
@@hightech-lowlifeanother tip, buy old windows machine from enterprise, probably xp/7 era and get cd keys, install, verify and upgrade to win10/11 free. All my thinkpad in family have windows pro by this process lol