The Windows upgrade had been a free upgrade for Windows 7 and 8 users until July 29th, 2016, at least for most people. Microsoft then started charging $119 for the Home Edition or $199 for the Pro Edition. For now, a backdoor has been left open, you can still get a no-cost upgrade to Windows 10. Read on and follow the link to a page for people who use assistive technologies.
You qualify for the free upgrade if you use assistive technologies. Assistive technologies, such as a magnifier to see the screen enlarged, a narrator to read the text in browsers or in a document aloud, keyboard shortcuts or an on-screen keyboard. Assistive technology provides additional accessibility to people who have physical or cognitive difficulties, impairments or disabilities.