The new operating system is Microsoft's first since 2012.
Windows 10, Microsoft’s first updated version of its computer operating system since 2012, will be offered as a free upgrade for most Windows users, the company said at a product unveiling Wednesday afternoon.
For a limited time — up to one year after the new operating system launches — Windows 7 and 8 users will get a free upgrade to Windows 10. In a live-streaming launch event, Microsoft MSFT announced the offer while also highlighting features of the new software, including the addition of Cortana — the Microsoft digital assistant found on Windows phones — to PCs. Windows 10 also brings the return of the Windows start menu, which had been removed from the previous iteration of the software.
Windows 8 was introduced in 2012, proving unpopular and failing to gain widespread adoption among Windows users. Microsoft later released an upgraded version, Windows 8.1, but that did little to boost the software’s user numbers.
Windows 10 is the first Microsoft operating system to hit the market under the tenure of new CEO Satya Nadella, who took over for Steve Ballmer last year.
The announcement by Terry Myerson, who runs Microsoft’s operating systems group, is a marked change for the company, which has charged for new versions of Windows, one of the main profit drivers.
The shift shows Microsoft is moving toward a frequently updated, subscription model for its flagship operating system, rather than major, paid-for upgrades every few years.
—Reuters contributed to this report.