While there was some confusion over Microsoft giving away Windows 10 to pirates, the software giant is now being clear about its free upgrade plans for Windows 10. We already know that Windows 7 and Windows 8.1 users will get Windows 10 as a free upgrade (providing you install within a year of July 29th), but Microsoft is introducing a new way for anyone to get Windows 10 free of charge. If you install the latest Windows 10 preview (build 10130) on a machine and use a Microsoft Account that's registered for the Windows Insider program then you'll get the final version of Windows 10 free. Windows 10 will stay genuine, so you can clean install the preview right now and simply upgrade to the final bits for no charge.

Read next: Our Microsoft Windows 10 review.

Microsoft's Gabe Aul confirmed this method on Twitter yesterday as part of a new blog post detailing some new changes to the way the company tests Windows 10. "As long as you are running an Insider Preview build and connected with the MSA (Microsoft Account) you used to register, you will receive the Windows 10 final release build and remain activated," says Aul. Microsoft will soon require testers to use a Microsoft Account to receive updated builds, and even when Windows 10 is finalized testers can opt-in and keep receiving future test versions in the coming months. So if you're running Windows XP or Windows Vista and you're looking to get a free copy of Windows 10, simply install the preview now and you'll get the final copy free once it's ready on July 29th.

Update, June 21st 9:45AM: Microsoft has updated its blog post today and removed references to "remain activated." The stealthy edit isn't acknowledged, and we've reached out to the company for comment.

Verge Video: Windows 10 build 10056 on a tablet