If you are looking to use Windows without a key, Microsoft actually allows you to download and install via the Media Creation Tool . While an unactivated version has minor cosmetic limitations (like a watermark and disabled personalization settings), it is a secure and official way to use the operating system.

“Create a windows.txt file with system info and send it over 10 km using a 900 MHz link.” Shortened with bit.ly in a PDF or forum post — but the link would be dead or private.

KMS activations are temporary. By design, a KMS client must check in with the server every 180 days. If you use a script that relies on a public external KMS server, and that server goes offline, your Windows installation will eventually lose its activation status. This can result in a black desktop background and persistent "Activate Windows" watermarks.