[Sebb767]

Technically a file system is just a special database. I think a better formulation of the authors point would be "the registry is a lot like a file system, even though a more traditional database approach or fully embracing it as a file system would have probably worked out better".

Also, they would have been able to at least improve the on-disk format with a major version; I highly doubt that the registry itself is backwards-compatible anyway and there are probably very few programs that access it directly.

[zamadatix]

That's a really good take on what the author was going for, I appreciate the take! I still disagree that it starting out as a filesystem or database has anything to do with why it's so crap 30 years later but it gets to the crux of the topic much quicker.

With how tightly the APIs for accessing the registry are coupled with the model and encodings of the registry, particularly the driver APIs for it, I don't think it would have been so easy to just swap out the back end without breaking something though (which Windows avoids like the plague) but maybe doable by someone more optimistic than me :). The real "rewrite" was the push for Universal Windows apps using the .NET platform which stores everything for the app in XML files and shadow directories instead of the registry. Of course that didn't take over quite like they hoped so they ended up back with using the registry they were trying to leave 10 years later.