When you start your PC the first code executed is the UEFI (from the English Unified Extensible Firmware Interface , meaning in French: "Unified extensible firmware interface"), worthy replacing the BIOS, from the English Basic Input Output System (in French : “Elementary input / output system”).
The UEFI first starts the hardware tests (equivalent to POST in BIOS) then searches for the boot information in the SRAM.
In UEFI Secure Boot is a protocol that makes it possible to secure the process of loading the operating system by recognizing (or rejecting) a digital signature associated with the OS and the Firmware.
Step 2: Windows Boot Manager
The Windows Boot Manager, which can be found in EFI \ BOOT \ BOOTX64.EFI is started.
The role of Windows Boot Manager is to launch the operating system, it can be found in the BCD (Boot Configuration Data) file located in / EFI / Microsoft / Boot / BCD.
You can consult the boot entries in UEFI or using the BCDedit command:
Step 3: Windows Loader:
The BCD points to the Windows loader (Winload.exe). This is by default in % SystemRoot% \ system32 \ winload.efi
The Windows Boot Loader can now launch the Windows kernel.
Click on the “Blank workbook” to open a virgin page.