The best thing about Windows 10 is that it's simply Windows, through and through. It's as if Microsoft realized that devaluing the desktop in Windows 8 was akin to sacrilege, and Windows 10 is its penance. At its core, it's a union of the best qualities of Windows 7 and Windows 8 -- the desktop features of the former with some of the touch-friendly aspects of the latter. It's no wonder Microsoft is calling it an operating system that's both fresh and familiar. It's easy to use with a keyboard and mouse, but it's even better with touchscreen computers. The Start menu is back! And new features like Microsoft's Cortana virtual assistant and Edge browser breathe new life into Windows. Microsoft is framing the OS as "Windows as a Service," meaning it's never quite done and constantly evolving. Most importantly, Windows 10 proves that Microsoft's dream of delivering a single OS that can work across computers, tablets and phones might actually come true.