Which Registry Hive is Loaded First during Windows Startup??

Where is the Bootmgr File Stored on the Hard Drive?

The BOOTMGR file itself is both readonly and hidden. It is located in the root directory of the partition marked as Active in Disk Management.

What is the Path and Name of the Log File Created when you Enable Boot Logging on the Windows 10 F8 Startup Settings Menu?

The Enable boot logging option starts Windows 11, 10, or 8 normally, but also creates a file of the drivers being loaded during the next boot process. The "boot log" is stored as ntbtlog. txt in whatever folder Windows is installed on, almost always C:\Windows.

What is the Name of the File that is Created when you Enable Boot Logging on Windows?

Enable Boot Logging.
Creates a file, ntbtlog. txt, that lists all the drivers that are installed during startup and that might be useful for advanced troubleshooting.

What is the Name of a Lean Operating System that can be Launched to Solve Windows Startup Problems and Provides a Graphical and Command Line Interface?

Windows RE provides a graphical and commandline interface.