Hi jms_797,
WinLogon.exe controls the whole startup process and the User Profile Service is started before GPO
Full Description of the Startup process:
Power-on self test (POST) phase
Initial startup phase
Windows Boot Manager phase
Windows Boot Loader phase
Kernel loading phase
Logon phase
Kernel Loading Phase The Windows Boot Loader is responsible for loading the Windows kernel (Ntoskrnl.exe) and the HAL into memory. Together, the kernel and the HAL initialize a group of software features that are called the Windows executive. The Windows executive processes the configuration information stored in the registry in HKLM\SYSTEM\CurrentControlSet and starts services and drivers.
The following sections provide more detail about the kernel loading phase
Logon Phase
The Windows subsystem starts Winlogon.exe, a system service that enables you to log on and log off. Winlogon.exe then does the following:
Starts the Services subsystem (Services.exe), also known as the SCM. The SCM initializes services that the registry entry Start designates as Autoload in the registry subkey HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Servicename.
Starts the Local Security Authority (LSA) process (Lsass.exe).
Parses the Ctrl+Alt+Delete key combination at the Begin Logon prompt (if the computer is part of an AD DS domain).
The logon user interface (LogonUI) feature and the credential provider (which can be the standard credential provider or a third-party credential provider) collect the user name and password (or other credentials) and pass this information securely to the LSA for authentication. If the user supplied valid credentials, access is granted by using either the default Kerberos V 5 authentication protocol or Windows NT LAN Manager (NTLM).
Winlogon initializes security and authentication features while PnP initializes auto-load services and drivers. After the user logs on, the control set referenced by the registry entry LastKnownGood (located in HKLM\SYSTEM\Select) is updated with the contents in the CurrentControlSet subkey. By default, Winlogon then starts Userinit.exe and the Windows Explorer shell. Userinit may then start other processes, including:
Group Policy settings take effect Group Policy settings that apply to the user and computer take effect.
Startup programs run When not overridden by Group Policy settings, Windows starts logon scripts, startup programs, and services referenced in the following registry subkeys and file system folders:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Runonce
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows\Run
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
SystemDrive\Documents and Settings\All Users\Start Menu\Programs\Startup
SystemDrive\Documents and Settings\username\Start Menu\Programs\Startup
Source:
https://stackoverflow.com/questions/13685960/wh...