Microsoft to give away Windows 10, unveils hologram glasses

Seattle

MICROSOFT Corp will give away its upcoming Windows 10 operating system as a free upgrade to users of the most recent versions of Windows and Windows Phone, as the world's largest software company tries to retain customers in the mobile era.

The "free" strategy is a calculated gamble for Microsoft, designed to put Windows in as many devices as possible. It would then make up for any lost revenue by selling services such as Office over the Internet, or cloud.