Microsoft just dropped a bomb that will echo through the world of software piracy for a long time: Windows 10 will be a free upgrade even for non-genuine versions of Windows.

"We are upgrading all qualified PCs, genuine and non-genuine, to Windows 10," Windows operating systems chief Terry Myerson told Reuters on Wednesday.

This means that all users running a pirated copy of Windows 7 or Windows 8 will be able to upgrade to Windows 10 — a stark contrast to Microsoft's anti-piracy measures in the past, which included an activation system as well as warnings and reduced functionality for Windows systems that were determined to be non-genuine.

In January, Microsoft announced that Windows 10 will be a free upgrade for users running Windows 7 or Windows 8. Non-genuine versions were not mentioned at the time. The catch is that Windows 10 will be free for the first year; after that, users will need to pay.

So why is Microsoft doing this now? The answer is simple: China. Hundreds of millions of users in the country are running a pirated version of Windows; with this move, Myerson says, Microsoft plans to "re-engage" those users.

While Reuters' report is focused on China, Microsoft has confirmed to Mashable that the free upgrade for pirated Windows versions will work globally.

"Anyone with a qualified device can upgrade to Windows 10, including those with pirated copies of Windows. We believe customers over time will realize the value of properly licensing Windows and we will make it easy for them to move to legitimate copies," a Microsoft spokesperson told Mashable in an email.

On Tuesday, speaking at the Windows Hardware Engineering Community (WinHEC) summit in Shenzhen, China, Myerson announced that Windows 10 will be available this summer in 190 countries and in 111 languages.