Image: Bloomberg

Microsoft is about more than Windows, said its CEO Satya Nadella, and the company's hardware plans are about more than just mobile.

Nadella was speaking in an interview with Bloomberg for the launch of his new book Hit Refresh.

Asked about the future of Windows for Microsoft, Nadella replied: "Windows, there's a billion users on Windows. Three hundred million PCs were sold last year and it continues to be a very significant part of what we do, but it's not the only part."

Microsoft later said the number was actually more than 1.5 billion Windows users.

Nadella's figure for PCs sold rounded up Gartner's 2016 estimate of 267 million shipments, which were down from 287 million in 2015. In May Microsoft revealed it had 500 million Windows 10 users.

In 2015, Microsoft had hoped for Windows 10 to be on one billion devices by 2018, but later admitted it would take longer.

The billion figure included PCs, laptops, tablets, Windows Phones, Xbox One gaming consoles, Surface Hub conferencing systems, HoloLens augmented-reality glasses, and various Internet of Things (IoT) devices.

But the Microsoft CEO stressed that Microsoft is a more diverse company these days, with a portfolio spanning LinkedIn, Office 365, Azure, and Xbox, which has 350 million Xbox Live subscribers.

Asked whether Microsoft would build a mobile device again in the future, Nadella referred to HoloLens, repeating his belief that the mobile devices of tomorrow won't resemble today's smartphones.

"Take HoloLens," said Nadella. "Is it a mobile device? Yeah, it is. It's untethered, it's battery powered, you wear it on your eyes. Microsoft will always be in this end-to-end computing experiences business, but our goal is to invent categories and reinvent categories.

"We will always invest in new hardware to create new categories," he said.

This story has been amended to add clarification from Microsoft of Nadella's comments. It said that there are currently over 1.5 billion Windows users.

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