19. Windows Vista
In late 2006, Microsoft introduced the Windows Vista operating system. Vista would later go down in history as one of the worst Windows operating systems of all time, with numerous problems around activation, security, performance, pricing, and more.
Conner Forrest has nothing to disclose. He doesn't hold investments in the technology companies he covers.
Conner Forrest is an analyst for 451 Research. He was formerly a Senior Editor for TechRepublic.