This year Microsoft introduced a new incarnation of Windows Genuine Advantage which would gradually disable Windows Vista installations as long as Microsoft thought the copies were not "genuine." As expected, there was a bit of an outcry especially as the WGA used with Windows XP had been such a disaster that Microsoft was actually the target of class-action lawsuits seeking relief from the draconian desktop shutdowns it imposed on wrongly accused counterfeit versions of the operating system.
So Microsoft has made some changes in the now-shipping Vista version of WGA. Instead of simply declaring counterfeit all copies of Vista that Microsoft can't prove beyond a shadow of a doubt are legitimate, Redmond has added a third option: "don't know." As far as I can tell, this doesn't change anything in the operation of the program, it simply changes the way customers will react to being notified that their copy is not considered "genuine."
Should the "don't know" (or, in Microsoft's words, "indeterminate") flag pop up, users will be directed to download tools that can further analyze their installation in an effort to determine whether or not they have a legitimate copy. Never mind that receipt you have from the vendor - or the purchase order you executed for a couple of hundred copies.
It's a lot like the current police vernacular of "a person of interest." It used to be we had innocent parties and suspects but evidently being labeled a "suspect" was too strong so now some folks are called a "person of interest". Since 90%-plus of those turn into suspects, what real difference is there? Newspaper stories talk about them as if they were suspects - even you think of them as suspects, don't you?
So when Microsoft tells you your operating system is "indeterminate" it's really saying "you're no longer innocent until proven guilty, you now have to prove your innocence to us."
So if this change doesn't really help you, since there'll be just as many false positives (only some will be false "maybes"), why the change? David Lazar, director of the WGA program let the cat out of the bag when he told InformationWeek: "[We want to make] the messaging and the self-help options so clear and simple that users will not need telephone support." Microsoft much prefers that you spend time and effort with its so-called "self-help" tools and not use its resources to solve the problem caused by its faulty software!