Windows can be installed without a license but must be activated online using a valid license within a certain time frame (128 days?). Windows 10 activation is

Windows can be installed without a license but must be activated online using a valid license within a certain time frame (128 days?). Windows 10 activation is done by device fingerprinting to match a license which is different from how windows was activated in the past. With previous versions of Windows you activated by providing a product key. Restore and Recovery discs are different form standard installation media, the kind you can download for free from Microsoft. R/R discs are custom builds from the OEM, who is required to have a software distribution license from Microsoft, and don't usually prompt for license activation. They circumvent the need for the user to input a key by either storing it on a recovery partition, in the BIOS, or hardcoding it on the media. > To use your analogy, it would be like you redistributing an encrypted book file that the publisher had emailed me when I bought my hard copy, but I couldn't open it anyway unless I had the key from the back cover. Not just distributing, selling without permission of the publisher and decryption keys are widely available online.