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.
Now this is not as simple as it seems, what could be the probable limitations? These downloads work only for those who have originally purchased it either directly from Microsoft site or from the authorized dealers. So it will not work for Windows 7 OEM System Builder media. And it seems that most of the times the Windows 7 installed is of this OEM version. Hence the retail key does not match and user gets stuck up at the verification step.
It has also been observed recently that the manufacturers of computers are providing restoral disks or ability to create a set of restoral disks instead of the Windows Installation disks with the new computers as is the case of Windows 7 OEM System Builder media. These restoral options have their own cons and they add lot of junk apps to the OS. So these users can also download the clear version of Windows 7 IOS from the site and get rid of the unwanted junk apps which are bloating their OS, the only requirement is a proper valid retail key, if users manage to get this they can download the software legally from the site.
A word of caution is that when user is downloading the software directly a valid retail key is the first requirement and once downloaded all the files and data will be washed from the computer so user need to keep a proper back up of the important data like drivers. This is available only for the Windows 7 version.