Microsoft officially announced Windows 8 Thursday at a massive event in New York City. Windows 8 will be available in 140 markets and in 37 languages on Friday. Users can start downloading Windows 8 at 12:01 a.m. and copies will be available in stores at midnight local time at retailers around the globe.

Existing Windows owners can upgrade to Windows 8 for $39.99. In addition to Windows 8 and Windows 8 Pro, Microsoft is also announcing Windows RT. Windows RT will come preloaded on ARM devices such as the Microsoft Surface tablet.

At the launch event, Microsoft CEO Steve Ballmer said that Windows 8 is ushering in a “new era for Microsoft.” Windows 8 is the first product of this new era.