We will file this item under 'Why has this taken so long?'
Microsoft filed a patent that describes a process for repairing corrupt software. The patent goes far beyond the traditional System Restore in Windows and uses a download capability to fix a software problem. Conceivably, this could be a critical milestone toward the achievement of an operating system that largely maintains itself and does not surprise its user with a note that some file is missing and that Windows isn't able to boot as a result. Windows has been prone to such problems especially during OS upgrade processes and even simple software updates that, for example, affected some Windows Vista SP2 users who tried upgrading IE8 to IE9.