Companies that transform our lives with one innovation (like Microsoft Windows) often find it difficult to repeat the same feat because everything - from product to revenue to culture - is built on top of that one big idea. This is the challenge Satya Nadella faced when he took over the reins at Microsoft. How could he ensure that the 43-year-old company seized new opportunities and warded off potential threats? The answer: Build the ability to hit refresh into the culture by focusing on mission, leadership and growth mindset.