If you see an Activate button, press it to start the activation process this should work and you should see 'Windows is activated with a digital license linked to your Microsoft account' under Activation on the page.First thing you need to do then is to select Start > Settings > Update & Security > Activation to check the activation status. You boot into Windows 10 if the upgrade worked.The process takes a while as the entire system needs to be downloaded and then installed on the device. Run the tool on the device that you want to upgrade and follow the on-screen instructions.Once completed, download the Windows 10 Media Creation Tool from the official download page on Microsoft's website.You can use a program like Paragon Backup & Recovery Free for that, or any alternative such as Macrium Reflect, or any of the other system backup tools for Windows. You need an option to restore the system if things go wrong, and you don't want to put all your trust into Windows' own recovery options. We strongly suggest that you create a backup of the system before you run the upgrade.Scroll down and you should see the activation status on the page. You may check this in the Control Panel > System and Security > System. You need to make sure that the license of the older version is genuine and activated.In case you are wondering how you'd be able to make use of the still existing offer, here are the instructions:

It should not come as a surprise that it is still possible to upgrade Windows 7 SP1 and Windows 8.1 devices to Windows 10 provided that these devices have a genuine license.

Today, I decided to re-run these tests to see if upgrades are still free.

Windows 8.1 to windows 10