One of the security experts at Google's Project Zero -- they look for security vulnerabilities -- set out to reverse engineer Windows registry, publishing 4 blog posts so far on what he's found. It's a lot of info and sources of info that will not interest most folks, but if you're into the tech aspects &/or coding you might find something of interest.
googleprojectzero.blogspot[.]com/2024/04/the-windows-registry-adventure-1.html
googleprojectzero.blogspot[.]com/2024/04/the-windows-registry-adventure-2.html
googleprojectzero.blogspot[.]com/2024/06/the-windows-registry-adventure-3.html
googleprojectzero.blogspot[.]com/2024/10/the-windows-registry-adventure-4-hives.html