Search notes:

smss.exe

The Windows Session Manager.
smss.exe is the first user mode process that is started by the Windows kernel (and is therefore sometimes compared to Linux' init).
The session manager starts subsystems, see value Required under registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\SubSystems.

See also

The value of BootExecute under the registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager.
The start value under the registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\driverName.
autochk.exe

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