Microsoft has created Microsoft Software Recovery webpage to allow Windows 7 users to download Windows 7 setup ISO files for free in order to create installation media such as DVD or bootable USB drive to install Windows 7.
You’ll need to verify your Windows 7 product key before start to download. You can also use the same webpage to send an email containing Windows 7 setup ISO direct download link which can be used to download the ISO file later. The download link will work for 24 hours only.
Microsoft Software Recovery for Windows