Although Microsoft has promised to release Windows 10 as a free upgrade to those with Windows 7 and 8/8.1, those who cannot upgrade will have to purchase a license.

The operating system will be available in 190 territories globally with existing Windows 8.1 and Windows 7 users having one year (i.e. till 29 July 2016) to upgrade to the new operating system.

Users will be able to reserve a free upgrade in the coming weeks.

Those users who cannot upgrade will have to purchase the license with the following pricing structure:

Windows 10 Home - $119

Windows 10 Pro - $199

To upgrade from Windows 10 Home to Pro will cost $99.

Source: TechRadar