Is it possible to use Windows without a key? Can you "activate" it strictly speaking? Usually, no—but you can extend the trial indefinitely or use a legal workaround for enterprise users.
Large businesses and schools use a server. If your computer is connected to a work or school network that has one, you can convert your Windows installation to "Volume License" mode using a generic key. how to activate windows without a product key
You don't want to pay $100+ for a license right this second. You lost your old key. Or maybe you are just testing a new build. Is it possible to use Windows without a key