How does it go from legitimate to pirated?
Hrmmm.... I have no idea. Maybe it didn't see anything the first check, and then it found something on one of the other checkups.
What I found interesting was:
When Microsoft believes a copy of Windows is pirated, the user begins to get a series of reminders that the copy isn't genuine. Such users also are barred from downloading noncritical updates, such as the new version of its Internet Explorer browser. But anyone who has signed up to automatically receive security updates, which repair flaws to prevent Internet attacks, will still get those fixes.