Microsoft (MSFT) announced its new Windows 10 operating system is running on more than 14 million devices in just a couple days after it was released via a free download. In a blog post, Microsoft said it has seen unprecedented demand for Windows 10, with positive reviews and customer feedback. The company said it is rolling out the operating system in phases, so it has not yet been delivered to everyone who requested it. Daniel Ives, managing director and analyst at FBR Capital Markets, said he views 14 million downloads as a solid number out of the gates and a positive indicator for future success on both the consumer and enterprise fronts. He added, 'Feedback has been healthy so far although its a long road ahead to get to one billion devices. While a lofty goal, we believe Microsoft has finally figured out the right formula with Windows 10 as the features around this flagship product, coupled by free downloads, has been the right one-two punch to drive adoption.' Ives said subscriptions and cloud remain the key to Windows 10 unlocking future revenue opportunities. The Windows 10 free upgrade landed in 190 countries on Tuesday, July 28.