Today, Microsoft has released a new Windows 10 build for Windows Insiders, and Brad includes a full write-up about what's new. But what I'm particularly pumped up about is a major switch the signal from product activation: With this particular build, Microsoft will let customers enter a Windows 7, 8, or 8.1 product key to activate Windows 10.

This can be a major change, and the one which I think will address an element that I and a great many other upgraders have experienced: Which is, when you clean install Windows 10 after previously upgraded (from Windows 7 or 8.1), it is supposed to auto-activate. But many times it does not, and when customers contacted Microsoft support, we were holding told they will have to install the previous OS again, and then upgrade again. To be clear, this is not how this system is supposed to work.

Here's how Microsoft describes the alteration.

"We have received a great deal of feedback from Insiders on making it easier to activate Windows 10 on devices that take advantage of the free upgrade offer to genuine Windows by using existing Windows 7, Windows 8 or Windows 8.1 product keys. In the event you install this build of the Windows 10 Insider Preview on the PC and this doesn't happen automatically activate, it is possible to enter the product key from Windows 7, Windows 8 or Windows 8.1 employed to activate the earlier Windows version for a passing fancy device to activate Windows 10 when you go to Settings > Update & security > Activation and selecting Change Product Key. If you do a clean install of Windows 10 by booting off the media, it's also possible to enter the product key from prior Windows versions on qualifying devices during setup."

If I'm looking over this correctly and not missing anything, it implies that you can use any Windows 7, 8, or 8.1 product key to activate upgrading or clean install of Windows 10. I suppose that certain keys like those given a PC will only work on the same PC for that this PC was created. But this still a large improvement over the thing that was already an extremely generous system. (Assuming it worked properly, that this did not continuously.)

This also calls into question the purpose of the free Windows 10 upgrade, however. As I've written in the past, the year-long free Windows 10 upgrade promotion was not ever about giving customers free copies of Windows 10. It absolutely was about getting as numerous PCs already out in the world as you possibly can upgraded to Windows 10. Which is, Microsoft is trying to remove as many older Windows versions from circulation as you possibly can in order to make it easier to keep the installed base current with new features and, more essential, security updates.

I purchase questions about all this the time. For example, this morning someone on Twitter inquired about the following (which has been edited for non-Twitter clarity):

"It can be nice if, when installing Windows 10, you could enter the product key from your previous version. I'm building a new PC and provide an unused Windows 8 upgrade license. And so i have to install Windows 7, Windows 8, then upgrade to Windows 10 before wiping and clean-install Windows 10."

Yeah, that you will find nice. Nevertheless it completely bypasses the point of the free Windows 10 upgrade, which isn't to give you a free copy of Windows 10 for a previous Windows license you won't ever used. It's to upgrade existing, in-use PCs to Windows 10.

Though the thing is, if this new policy 's what I believe it's, this guy's wish comes true: They can use the product key from the Windows 7 license and just clean install Windows 10. There's no need to upgrade too many times and then clean install.

This may require lots of testing. And I am very happy to do that.