Hardware technology is not up to the task yet. Hardware is replaced in as little as three months in my systems and some of the replaced hardware goes for too much to consider paying on a subscription basis at that rate (the vendor would lose money) as well as removing the freedom of the owner to replace hardware as he sees fit while being tied to a contract. Most of the hardware available now has DRM code already imbedded so its inevitable that MS tries this but I wont be participating.