While announcing his company plans to offer Windows 10 as an upgrade to Windows 7, Windows 8 and 8.1 users free of charge for the first year, Nadella described Windows-as-a-Service as "a pretty profound change", both in its development and how it will be received by customers.
"It's not just simple mechanics, although there are big changes in terms of our development methodology, our deployment policy, our servicing," Nadella said.
"It's much more fundamental than that. For us, it is about aligning our goals of successful Windows with customers and their experience and engagement with Windows. That's what Windows-as-a-service means."
Nadella also suggested that Microsoft was trying to go back to its roots in innovation and serving its user base.
He said: "The fact that a billion-and-a-half users use Windows is incredible. And we want to be able to serve that base and grow that base with the innovation. To me, the brand is a reflection of the innovation that people love. And that's what I want us to be focused on."
Executive vice president for operating systems Terry Myerson followed up Nadella's comments by advancing a potential catch-phrase for Windows 10: "a more personal computer". Among his company's aims, Myerson said, was to make Windows more approachable and more natural to users.
"So we kind of know what we stand for; we know what we are pursuing," Myerson said. "And we think it's worthy of the dedication we put into it."
Bob O'Donnell, chief analyst with Technalysis Research, said that he was impressed with Microsoft's ability to convey a convincing message in favor of the new operating system.
O'Donnell believes there will be something in Microsoft's Windows 10 message that speaks to users' basic needs, the simple return of the Start Menu being the most obvious. But the inclusion of Cortana, the voice-driven personal assistant from Windows Phone, he feels will speak to people who have difficulty getting their Windows to do everyday tasks, like find certain groups of pictures from their media libraries.
"All those things together creates a much smarter experience for people," said O'Donnell, "and I think it makes them rethink how they use their PC."
The convergence of all these changes, O'Donnell predicts, presents a compelling enough value proposition for existing PC owners and businesses to upgrade from Windows 7, or perhaps even older systems. However, he added, "the challenge that remains - and I'm still concerned - is, I don't think this changes the needle on mobile phones. But the PC and tablet story is very strong, and the fact that it's all free, I think, is just going to encourage doing additional feature updates."