Microsoft have broke the Digital River .isos, there are not working download links to Windows Vista and Windows 7 now. 🙁
They have been replaced the Windows 7 Digital River Download Links by a non-functional Microsoft Software Recovery Tool: http://www.microsoft.com/en-us/software-recovery
This tool is designed to work with only Retail licenses and in my testing it doesn’t even work with these. They have deliberately forced the input of a product key deliberately blocking out the Windows 7 OEM userbase. This has done a huge disservice to the Windows 7 userbase. In particular as many people will need to Reinstall their Windows 7 OEM licenses in order to qualify for their free upgrade to Windows 10 and it takes some time to procure installation media from OEMs. The .isos should be available without entry of a product key for the first year of Windows 10 release, so the OEM userbase can safely migrate.
Windows Vista can essentially be thought of as End of Life albeit 2 years prematurely.
More details of the problems are listed here: http://answers.microsoft.com/en-us/windows/forum/windows_7-windows_install/microsoft-software-recovery-tool/95ac28f9-bd2d-4bb3-9f70-a62fecc56316