According to the latest blog post by Gabriel Aul, head of the Windows Insider program, anyone will be able to get a copy of Windows 10 for free, besides current Windows 7 and 8.1 users. What you’ll need to do is to download and install Windows 10 Insider Preview. Once Windows 10 hits final release on July 29th, your Insider Preview OS installation can be upgraded to it. A requirement for the free upgrade is to have a Microsoft Account (MSA) connected to your PC (and Insider Preview program), instead of just using a local user account. UDPATE: In addition, you’ll have to continue using OS as a Windows Insider and keep getting preview builds after 7/29 in order to keep Windows 10 running on your machine.
“Windows Insiders running the Windows 10 Insider Preview (Home and Pro editions) with their registered MSA connected to their PC will receive the final release build of Windows 10 starting on July 29th. This will come as just another flight. I’ve gotten a lot of questions from Windows Insiders about how this will work if they clean installed from ISO. As long as you are running an Insider Preview build and connected with the MSA you used to register, you will receive the Windows 10 final release build and remain activated. Once you have successfully installed this build and activated, you will also be able to clean install on that PC from final media if you want to start over fresh,” Aul posted.