Microsoft is very slow to adjust to market pressures which may become it's undoing. The world is networked now. An OS has become largely irrelevant while the browser has become the new OS.
People no longer buy an eternal license of Windows anymore. Besides that model never made sense due to continuous Windows updates. Also new PC's tend to be sold with an OEM license and only savvy PC users know how to get a box without the Microsoft tax.
Adobe got it right with their rental of their latest software suite. Priced at $40 a month you get access to thousands of dollars worth of software for as long as you keep paying.
Microsoft is well overdue to do the same. An monthly or annual Windows rental for X dollars for their latest Windows OS with maybe the first year free or at reduced cost. Not only does it remove the Windows tax from ever more competitive priced hardware but it also makes it possible for Microsoft to innovate faster and keep their Windows OSes out there up to date.
Look at Youtube! Over the years it has drastically changes the look and feel but Google did it in many small steps, slowly easing users in the direction it wants to go. If Microsoft had done this with Windows they would not have the resistance to the new Metro interface they experience today. Hardware suppliers would embrace the "free" windows OS as it allows them to compete again against other free operating systems.
Consumers win too because they don't need to fork out for a full new license every few years while being able to use the latest OS without the need to perform massive monolithic upgrades.