微软正式发布Windows10

These kids won't have to remember passwords or obsess about security, because these kids will grow up with Windows 10.

Microsoft is marketing windows 10 as a fresh but familiar operating system. One that anticipates the future needs of today's children.

Microsoft CEO Satya Nadella explains.

"Windows 10 ushers in an era of more personal computing in a mobile first, cloud first world. We're building into Windows, that's seamless cross over across devices as you move around at home and at work. "

New versions of Windows usually ignite sales of personal computers but the last update to windows was widely considered a miserable failure.

Tech analyst Bob O'Donnell says with PC sales sliding four years in a row, Microsoft and PC manufacturers are looking at Windows 10 to set off sparks.

"Microsoft needs a fix because Windows 8 didn't do very well and as a result they really got a lot of egg on their face. And this is their attempt to save face, to bring back together pieces that people liked and knew about windows into a new environment. "

Windows 8 detractors say they're relieved to hear Windows 10 has brought back their beloved start menu. It also features a virtual assistant called Cortona…similar to apple's Siri…except you can talk to Cortana on a wide range of devices, including your computer.

"Hey Cortana email…..what's the subject of your email? Dinner plans"

Tech analyst Bob O'Donnel says the feature he's most excited about is windows 10's facial recognition feature.

"The coolest thing Windows 10 offers is Windows Hello which is a biometric authentication mechanism whereby you can walk up to your computer and if you have the appropriate 3d camera built into your computer you can walk up to your computer it will recognize your face and log you in"

People lined up early in the morning on launch day at Microsoft stores. We spoke to some of them who came for free consultations to see if their pcs are windows 10 accessible

(Woman) "I always try to keep my systems updated to the latest but I'm excited about Cortana."

(Man) "Windows is a nice mature operating system. I don't think people give it its due."

To jump-start adoption of Windows 10 the company is offering free upgrades to the vast majority of home users. Microsoft has set a target of 1 billion devices running windows 10 within three years of launch.

For cri, I'm Rachel Silverman in san Francisco