672 Computer Service and Repair
system is installed on a computer. However, the Boot Manager still runs even if it
does not appear on the display. The default for the boot manager is 30 seconds, but
the delay is reduced to approximately 2 seconds when only one operating system is
present. It is during this two-second interval that the [F8] key can be pressed to
interrupt the boot process causing the
Advance Boot Options
menu to appear. The
Advanced Boot Options
menu is similar to the one in Figure 15-5.
If you do not press [F8] within the two seconds after completion of the POST,
the operating system will quickly load the Windows Boot Loader (winload.exe),
the Kernel (ntoskrnl.exe), and the Session Manager (smss.exe), which results in
the familiar Windows graphical user interface. The
Advanced Boot Options
menu cannot be accessed once the computer reaches this point. You must restart
the computer to access the
Advanced Boot Options
menu with the [F8] key.
You may start pressing the [F8] key before POST is finished. This will usually
automatically start the
Advanced Boot Options
menu. The Boot Manager then
passes control to the Boot Loader.
Boot Loader phase
In this phase, the Windows Boot Loader (winload.exe) first loads the kernel
(ntoskrnl.exe) into RAM, but does not execute it yet. Next, the hardware abstract
layer file (hal.dll) is loaded into RAM as well as the system registry hive. Certain
key services are started to support various device drivers that are required
during the boot process. Lastly, the kernel (ntoskrnl.exe) is executed and takes
over operation of the computer system.
Kernel loading phase
After the kernel (ntoskrnl.exe) is executed, the kernel and hardware abstract
layer (hal.dll) work together to communicate with software applications, drivers,
and hardware. Driver files that do not require user security clearance are
typically loaded. For example, the driver and services required to minimally run
the printer are loaded at this time.
Now the kernel and hardware abstract layer work together to process
information stored in the registry which will be required to complete the boot
process. The kernel creates a new registry key which contains information about
Windows Boot Manager
Choose an operating system to start, or press TAB to select a tool:
(Use the arrow keys to highlight your choice, then press ENTER.)
Earlier Version of Windows
Microsoft Windows Vista
To specify an advanced option for this choice, press F8.
Seconds until the highlighted choice will be started automatically: 22
Tools:
Windows Memory Diagnostic
ENTER = Choose TAB = Menu ESC = Cancel
Figure 15-28.
The Windows Boot
Manager menu will
appear by default if
there are multiple
operating systems on
the computer.