Windows XP Boot Process.ppt

Windows XP Boot Process 70-270: MCSE Guide to Microsoft Windows XP Professional Booting Windows XP (Page 1) Boot process phases: Boot phase begins when computer is first powered on Or begins when Restart is chosen from Shut Down Windows dialog box Windows XP load phases Begins when boot phase is completed Configuration is selected Booting Windows XP (Page 2) Boot Phase Steps Power-on self test (POST) Initial startup Boot loader Select operating system Detect hardware Select configuration Windows XP Load Phase Load the kernel Initialize the kernel Services load Windows XP system startup Log on Power-on Self Test (Page 1) First step in boot sequence (the POST) for any computer with an operating system Determines: Amount of real memory that exists Whether or not all necessary hardware components are present and functioning The specific tests vary depending on how the BIOS (Basic Input/Output System) is configured Power-on Self Test (Page 2) If POST is successful, computer boots itself If the tests are unsuccessful, the computer reports error by: Emitting a series of beeps (number of beeps identifies the error—differs from one BIOS to another) Also possibly might display error message and a code on the screen Power-on Self Test (Page 3) Software that performs POST resides in called the CMOS (complementary metal oxide semiconductor) Battery-powered chip that also can hold basic configuration information so POST can check installed RAM, number and type of hard drives, type of keyboard and mouse, the boot sequence (Which drive first?), etc. In Windows XP, BIOS no longer stores information about devices and drivers connected to system (replaced by the HAL) Power-on Self Test The following screen shows results of sample successful POST completion Power-on Self Test Power-on Self Test (Page 4) After POST completes, each adapter with a BIOS performs its own self-test (POST), i.e. Video card SCSI (small computer system interface) cards which are interfaces that provide