Who wouldn’t want a free copy of Windows 10? Microsoft has already said Windows 7 and Windows 8.1 users will get the update a gratis when it rolls out on July 29 (you’ll have to install it within a year). But what if you don’t run the latest two versions of Microsoft’s desktop software? What if you’re running Windows XP, or, *gasp*, Windows Vista?

Microsoft this week said that anyone who installs the latest Windows 10 preview (build 10130) and uses a Microsoft Account that’s registered for the Windows Insider program will get the final Windows 10 version for free.

What’s great is that users who install the Windows 10 preview right now can do a clean install, and then get the final update at no charge. Microsoft’s Gabe Aul confirmed the news in a recent blog post, saying copies will remain activated if you meet the requirements. Microsoft is giving consumers every opportunity to try the new OS out, and the fact that the update will be free is the icing on the cake.

There will be plenty of different versions of Windows 10 when it’s officially released—for consumers, businesses, and pro users—but for consumers, July 29 will be a good (and free) day. Windows 10 includes a number of improvements, including Microsoft Edge, Cortana integration and more.