Table of contents
Resource manager startup phase
BIOS/UEFI stage
When the computer is powered on, the BIOS or UEFI performs hardware initialization and performs POST self-test.
BIOS/UEFI looks for the boot device, usually the hard drive.
The operating system's boot loader (Windows Boot Manager) is loaded into memory.
Windows Boot Manager stage
Windows Boot Manager is responsible for displaying the boot menu and allowing users to select startup items, such as different versions of Windows or other operating systems.
After user selection, Boot Manager loads the boot loader for the selected operating system.
Boot loader phase
The boot loader (such as Winload.exe) is loaded into memory and it is responsible for loading the Windows kernel.
Windows kernel loading phase
The Windows kernel (ntoskrnl.exe) is loaded into memory.
The kernel initializes system components, establishes memory management, device drivers, etc.
The kernel creates a session manager process (Winlogon.exe).
Session manager startup phase
The session manager (Winlogon.exe) is responsible for user login.
Winlogon displays the login interface and the user enters credentials.
Winlogon authenticates the user and loads the user profile.
User login stage
User configuration files include the user's desktop settings, program startup items, etc.
Start user-level processes such as system tray, network connections, etc.
Resource manager startup phase
Windows Explorer (Explorer.exe) starts and is responsible for loading user interface elements such as the desktop, taskbar, and desktop icons.
User desktop display stage
Eventually, the user's desktop appears and the user can start using the computer.