Windows 10 to get 'holographic' headset and Cortana

Microsoft has revealed that Windows 10 will bring its voice-controlled assistant Cortana to PCs.

It also unveiled a headset that it said would one day project the operating system over views of the real world.

In addition, the firm announced that the OS upgrade would be offered free of charge for devices running Windows 8, Windows 7 and Windows Phone.

The offer, which is limited to the Windows 10's first year of release, may aid its adoption.

It marks a change in strategy from Microsoft's previous policy of charging for major updates, and could help avoid a repeat of the relatively slow uptake of Windows 8.

One analyst suggested the firm had needed to renew interest in its ecosystem.

"Overall, we know that about only about 10% of computers are running Windows 8 and the adoption rate among companies is similar or lower," said Frank Gillett, an analyst at the Forrester consultancy.

"Developers are not paying much attention to Windows for mass market consumer apps, and you could even argue that for enterprise software most of the energy is going into mobile apps for iPad and Android tablets.

"Windows 10 is in effect a huge invitation to software developers to write exciting, powerful applications that will draw consumers.

"My hunch is that they can succeed in getting a new generation of PC and tablet applications. The challenge is getting people interested in its phones."

Holographic helmet

Microsoft's chief executive Satya Nadella said the HoloLens headset represented a "magical moment" of "category creation" that developers lived for.

The wearable tech's augmented reality see-through lenses represent a major leap forward over Google Glass and other existing eyewear - assuming the machine lives up to its on-stage demo, in which computer-generated elements appeared in the world surrounding the wearer.

The company said that the final version of the machine would not need to be linked to other devices to work, and should be released within Windows 10's "timeframe".

It revealed Nasa was already working with the kit, and said the US space agency hoped to start controlling its Mars rovers with a prototype version as soon as July.

Other demos involving the machine included the wearer:

• playing Minecraft with the video game's graphics appearing over living room furniture
• seeing a Skype video appear as if it was taking place on a building wall
• creating a model of a drone, which she saw in front of her face while shaping it by moving her hands and giving voice commands

"The true innovation HoloLens delivers will be determined by developer commitment in the months and years to come," commented Geoff Blaber from the CCS Insight consultancy.

"Windows 10 is a defining moment for Satya Nadella early in his tenure as CEO.

"The collaboration required to deliver HoloLens to market is an encouraging sign that he's breaking down the silos that slowed innovation and stalled execution in recent years."