Windows

"Counterfeit", Microsoft says, about a disk made from their own free downloads and only usable on a machine already infected with Genuine Windows®.

This bullshit is why you shouldn't use Windows, no matter how many non-kitten-eating announcements and events Satya Nadella puts on to show that he's not Steve Ballmer. Sooner or later, Microsofties will always show their true nature and eat a kitten.