66 Computer Service and Repair
Windows Vista and Later Boot
Sequence
Starting with Windows Vista, Microsoft
made several changes to the boot sequence. First,
Windows Vista and later operating systems can
boot from the BIOS or UEFI. This section focuses
only on the BIOS-based boot sequence.
Look again at the table in Figure 2-31. The
second column lists the major phases of the
Windows Vista, Windows 7, and Windows 8
boot sequence. Notice that after the POST,
Windows progresses through the initial startup
phase in similar fashion as the Windows NT-based
operating systems. However, the next phase for
Windows Vista, Windows 7, and Windows 8 is the
Windows Boot Manager phase.
In this phase, the Windows Boot Manager
(bootmgr) reads a registry-type file called the Boot
Configuration Data (BCD) file. This file stores
boot configuration information, such as the names
of the operating systems to list in a boot menu,
the amount of time the boot menu should be
3. The MBR loads the operating system loader,
ntldr.
4.
Ntldr
reads the
boot.ini
fi le.
5. If the
boot.ini
fi le contains a reference to a
SCSII disk drive system, the
ntbootdd.sys
fi le is
loaded.
6.
Ntldr
calls the
ntdetect.com
program.
7. The
ntdetect.com
program detects system
hardware information and passes the
information to ntldr.
8.
Ntldr
passes the hardware information and
control over to ntoskrnl.exe.
9. The
ntoskrnl.exe
program loads the device
drivers and hal.dll, and then initializes the
computer settings using the values stored in
the system registry.
10.
Winlogon.exe
loads, allowing the user to begin
the logon process.
11. The user successfully logs on to the computer.
Windows NT-Based
Boot Sequence File
Description
boot.ini File used to identify the default operating system and other
operating systems if more than one is present. The
boot.ini
fi le
has been replaced by the Boot Confi guration Data (BCD) fi le in
Windows Vista.
bootcfg.exe Used in dual-boot and multiple-boot systems to allow the user
to select which operating system to boot.
hal.dll
Provides information and supports communication between
software applications and hardware devices. Software applica-
tions are not allowed to directly communicate with hardware.
Loads at the same stage as the kernel, and then works directly
with the kernel.
ntbootdd.sys The driver used to communicate with hardware devices that do
not communicate directly with BIOS, such as SCSI drives and
some ATA drives.
ntdetect.com File responsible for identifying hardware information for ntldr.
Ntdetect.com
has been merged into the Windows Vista kernel.
ntldr
File responsible for loading the operating system.
Ntldr
has been
replaced by the Windows Boot Manager in Windows Vista.
ntoskrnl.exe The core of the operating system, referred to as the kernel.
winlogon.exe The fi le that controls the system logon by the user.
Goodheart-Willcox Publisher
Figure 2-32.
Windows NT-based
(Windows 2000
and Windows XP)
boot sequence and
configuration files.