Microsoft allows anyone to download Windows 10 for free and install it without a product key.Yes this is true until Microsoft change the plan. Now the question is how to Download Windows 10 and Install it Without a Key. You need ISO of windows 10 and you can download it directly from Microsoft, and you don’t even need a product key to download a copy. There’s a Windows 10 download tool which will help you create a USB drive to install Windows 10. Steps . How to download windows 10 ISO from website for free Click here for Microsoft link for windows 10 ISO. Once page is opened click on Download Tool now It will download MediaCretionTool2004.exe Install MediaCreationTool2004 to your windows system. It will ask you two options Upgrade this PC now and Create installation media (USB flash drive, DVD, or ISO file) for another PC select second option - Create installation media (USB flash drive, DVD, or ISO file) for another PC Next page will ask you about Language. Edition, Architect