Microsoft Software Recovery Site allows legal download of Windows 7 ISO format only on verification with a valid retail product key.
Windows has made life easier for users of Windows 7 ISO who have lost or damaged their original installation DVD, by direct downloading it from Microsoft Software Recovery website. However, the main hitch is that users need to unlock the download first by a retail product key. This is the verification key and only once this step is cleared user can download the Windows 7 ISO format. The process seems to be very easy and simple and within 3 steps the download is completed. The ISO file can be used to install windows in a virtual device, burn the data in a new DVD or create even a bootable USB flash drive so as to help in future installation of the ISO.Full Article