writes "On Tuesday, Microsoft was granted US Patent No. 7,536,726 (it was filed in 2005) for intentionally crippling the functionality of an operating system by 'making selected portions and functionality of the operating system unavailable to the user or by limiting the user's ability to add software applications or device drivers to the computer' until an 'agreed upon sum of money' is paid to 'unlock or otherwise make available the restricted functionality.' According to Microsoft, this solves a 'problem inherent in open architecture systems,' i.e., 'they are generally licensed with complete use rights and/or functionality that may be beyond the need or desire of the system purchaser.' An additional problem with open architecture systems, Microsoft explains, is that 'virtually anyone can write an application that can be executed on the system.' Nice to see the USPTO rewarding Microsoft's eight problem-solving inventors, including Linux killer (and antelope killer) Joachim Kempin, who's been credited with getting Microsoft hauled into federal court on antitrust charges."
Sounds like the mechanism by which Microsoft sells one version of Vista to all users, and lets users upgrade to higher-tier flavors of the OS after cash changes hands.