Microsoft does not publicly list Version 1507 on their standard download pages anymore. They force users toward the latest version. However, Microsoft maintains a specific hidden portal for older versions for Enterprise/LTSB customers, which is accessible to the public if you know the trick.
When users search for an "updated" Windows 10 1507 ISO, they are usually looking for a version of the original release that includes all the security patches and bug fixes up until the present day. windows 10 version 1507 iso updated
If you need legacy driver support, often or Windows 8.1 Embedded is a more secure choice than 1507. Microsoft does not publicly list Version 1507 on