Sunday, August 5, 2012

Windows 7 Startup Process





Windows 7 start up process is described below:



The normal startup sequence for Windows 7 is:
  1. Power-on self-test (POST) phase.
  2. Initial startup phase.
  3. Windows Boot Manager Phase.
  4. Windows Boot Loader phase.
  5. Kernel loading phase.
  6. Logon phase.
 
Windows Boot Loader Phase:
  1. Loads the operating system kernel, Ntoskrnl.exe, but does not yet run it.
  2. Loads the Hardware Abstraction Layer (HAL), Hal.dll. This will not be used until the kernel is run.
  3. Loads the system registry hive (System32\Config\System) into memory.
  4. Scans the HKEY_LOCAL_MACHINE\SYSTEM\Services key for device drivers and loads all drivers that are configured for the boot class into memory. The Windows Boot Loader does not, however, initiate the drivers. Drivers are not initiated until the kernel loading phase.
  5. Enables paging.
  6. Passes control to the operating system kernel, which starts the next phase.