timmmay: Isn't W10 insider free for anyone to use still?

"And it's those preview builds that Windows Insiders will freely receive on a regular basis. Each preview build expires at a certain point, but Microsoft promises that it will be replaced by the next build. So in essence, those who wish to remain in the Windows Insider Program can get Windows 10 for free, but the version you run will always be a prerelease build, in other words a non-activated beta product.

"Since we're continuing the Windows Insider Program you'll be able to continue receiving builds and those builds will continue to be activated under the terms of the Windows Insider Program," Aul said. "We provide ISOs for these builds for recovery from any significant problems, but they are still pre-release software.""