I am on a 14-day trial with Parallels Desktop. For a new freelance gig, I need to download Windows. When I follow the Parallel prompts, I am taken to the Microsoft purchase site. But as with the Paralells software, I am not ready to BUY. I want to see how the two programs work together before making a purchase. I believe I can download an earlier version of Windows for free that will operate with the Parallels software, How can I do so by ignoring the Parallels prompt to BUY Windows?