Here’s how to get the upgrade at no charge:
From your Windows 7 or 8.1 device, go to the webpage entitled “Windows 10 free upgrade for customers who use assistive technologies.” Click on the Upgrade now button. Run the executable file to install the upgrade.
Microsoft then displays a series of screens that take you step by step through the set-up process. Follow the screens until Windows 10 is comfortably nestled into your device.
At no point during the upgrade does Microsoft ask for proof that you actually use any of the assistive technologies. So the upgrade seems to be accessible to any Windows 7 or 8.1 user who still wants to get Windows 10 for free. Apparently, you can let your conscience be your guide, though Microsoft hopes otherwise.