Microsoft's desktop operating system has been their cash cow for decades but it seems that the bets with Windows 10 did not completely pay off. Three years ago, Satya Nadella had a vision that consumers will fall in love with Windows 10 all over again. The company also claimed that Windows 10 will be used on a billion devices in 3 years. What actually happened has been a stark difference. Microsoft shot for the stars but missed by a long mile.