The official announcement says the new software will launch globally. 

 

All existing Windows 7 and Windows 8/8.1 users will have one year from the release date to take advantage of the free upgrade.

 

The new version, which features the return of the Start menu, will run across computers, tablets, phones, and gaming and entertainment devices.

 

Once a device is upgraded to the next-generation system, Microsoft says it will continue to keep it up-to-date for the supported lifespan of the device for free.