Microsoft continues to adapt to a world that nearly left it behind. It used to be that if you used a computer, you used Windows. But Windows was eclipsed by a mobile revolution led by the iPhone and expanded worldwide largely due to widespread Android adoption.
And consumers and institutions, like schools, are turning to Google's Chromebooks as opposed to cheaper laptops running Windows.
Windows 10 with Bing is a part of Microsoft trying to recoup some of that lost ground.
There's a lot riding on Windows 10 for Microsoft. Windows 8 famously eschewed the classic Start Menu, which angered many longtime Windows users. Microsoft is backpedaling on that change, and a new, enhanced version of the Start Menu returns in Windows 10. It's also streamlining the operating system to work across phones, tablets and PCs.