An option to buy it will, however, be available
Microsoft has a goal of bringing Windows 10 on 1 billion devices by 2017, and there's no doubt that the number one priority right now in Redmond is to upgrade as many Windows 7 users as possible.
But one of the biggest challenges is to convince those running a non-genuine copy of Windows 7 to purchase a Windows 10 license and go legal, so Microsoft is still looking into ways to make the transition more appealing.
Offering Windows 10 free of charge to pirates would be the best way to convince them to upgrade, but for the moment, Microsoft's not willing to do that. Instead, an easy way for Windows 7 users to purchase Windows 10 will be offered as part of an experiment in the United States, which could then be expanded to the whole world.
Until now, no matter if you were running genuine or non-genuine Windows 7, you were offered the upgrade to Windows 10. If your copy of Windows 7 was legitimate and you decided to upgrade, Windows 10 automatically activated once installed. Otherwise, you received a trial version that prompted you to activate at every system reboot.