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.

• Control Sets: The Windows Boot Loader reads control set information from the registry key HKEY_LOCAL_MACHINE\SYSTEM, which is stored in the file %SystemRoot%\System32 \Config\System, so that the kernel can determine which device drivers need to be loaded during startup. Typically, several control sets exist, with the actual number depending on how often system configuration settings change.
• Session Manager: After all entries that have Boot and Startup data types are processed, the kernel starts the Session Manager (Smss.exe), a user process that continues to run until the operating system is shut down.