Microsoft forgot (and still forget) the documentation for Windows - if you want a nice A-Z reference for the bootloader, or kernel, or shell or IIS's configuration file or half the command-line tools, you're usually out of luck. The official place is often an inaccessible, badly-written knowledgebase article written from a task-based, usually GUI-based perspective.
It never mattered that they'd implemented a more coherent system full of better ideas, because the only way they'd tell you about it is through the GUI.
The MSDN CDs from 20 years ago were really good for a complete programmer's reference, but 1) I'm not sure how well they kept that up and 2) I could never find anything as comprehensive for sysadmins.