I am sure like many others, if you have a setup that is running one of the more recent Windows operating system you probably go this message as well to register for a free software update for Windows 10 coming on July 29, 2015. I am one of those people who are still using Windows 7 as I never found the need to upgrade to Windows 8.
Since this is a free offer, it almost feels silly to not take advantage of it. I am always worried though about compatibility issues in upgrading to a new operating system. I have a lot of expensive software such as the Adobe suite as an example where it would be extremely inconvenient if the programs became unusable simply because of the upgrade.
I don’t think you have to actually register with this form to get the free copy as it seems more like a way to simply try and get as much people to upgrade on day one as possible. Microsoft seems pretty aggressive with this since they are offering it for free. Still makes me think if this is one of those scenarios where taking something for free will end up costing you more in the long run.