Microsoft really wants you to install Windows 10, because they really want to reach their stated target of Windows 10 running on one billion devices within the first three years.
To help prod us out of our apathy, they are offering Windows 10 as a free upgrade for the first year to existing Windows 7 and 8 users, and - according to a new ZDNET article - they are quietly offering Windows 10 for free to anyone signed up for the Windows Insider Program. Whether or not you already have a licensed copy of Windows 7 or 8.
A pretty sweet deal, if you are a Windows person. In fact I will probably take advantage of the offer for our home PC, which currently has Windows 7. I was going to upgrade it to an SSD this summer, so it would be a good time to upgrade the OS as well.