They definitely sell retail copies of Windows, and someone must be buying them, or else I can't imagine the retailers would bother stocking them. For example,

They definitely sell retail copies of Windows, and someone must be buying them, or else I can't imagine the retailers would bother stocking them. For example, a good amount of the people that have Macs also need to run Windows virtual machines (or Bootcamp), and the primary way to do that is to buy a retail copy of Windows. I can't imagine that's a very high percentage of revenue, but I wouldn't say that nobody buys Windows directly.