Chapter 2 Operating Systems 43
file system maintains a file table of all areas on
the disk, and it tracks which areas are used and
which are not. File systems are covered in greater
depth in Chapter 9—Storage Devices.
The file systems with which you should be
familiar are FAT12, FAT16, FAT32, and NTFS. The
default file system used by Windows operating
systems since Windows XP is NTFS. The FAT16
and FAT32 file systems are still available for
use in formatting partitions under the control
of Windows XP and Windows Vista. FAT is still
an option for Windows 7 and Windows 8 when
formatting flash drives. As you study operating
systems more in-depth, you will see the need for
other types of file systems.
You need to be familiar with all available
file systems in preparation for the A+
Certification exams.
A+ Note
Configuration Files
When a computer system is configured, the
type of hardware and software the system has
planned for use is recorded in a configuration
file. Configuration files contain information such
as the amount of memory and the type of video
adapter present in the system. Configuration
information is stored in the
config.sys
file of DOS
systems. The
config.sys
file is still used in newer
operating systems, but it is included only to
support legacy software applications.
Early Windows systems stored configuration
information in the
win.ini
and
system.ini
files.
Software applications also stored configuration
setting in
.ini
files. These configuration files are
replaced by the Windows registry settings for the
Windows 95 and later operating systems. Many
computer systems still contain
.ini
files to maintain
a downward compatibility with some software
programs.
The registry is found in Windows 95 and later
operating systems. The registry is essentially a
database that stores configuration information. The
major sections of the registry are listed as follows.
• HKEY_CLASSES_ROOT: Object linking and
embedding (OLE) information and how fi les
are associated with each other.
• HKEY_CURRENT_USERS: Information for the
current user of this workstation.
• HKEY_LOCAL_MACHINE: Information specifi c
to the local computer.
• HKEY_USERS: Information for each user of
this workstation.
• HKEY_CURRENT_CONFIG: Display and
printer settings.
The registry is accessed by entering
regedit
in the
Run
dialog box found in the
Start
menu
or by entering
regedit
at the command prompt.
Figure 2-9 shows the Windows XP Registry Editor.
Changes in the registry
can completely disable
your computer operating
system. Do not experiment with registry settings
unless under supervision of your instructor.
There are two main registry files:
system.
dat
and user.dat. The
system.dat
file contains
information about the computer settings. The
user.dat
file contains information about individuals
who use the computer. Registry files can be
copied to disk, installed on another computer,
backed up, and modified. The registry is repaired
through the System Restore utility. Rarely does a
technician need to access the registry files directly.
When a technician does access the registry
files, it is usually as part of repair steps outlined
by Microsoft on its TechNet website. Direct
modification of the registry should be a last resort
effort.
Microsoft Windows Operating
System
The most widely used operating system
is Microsoft Windows. You will encounter
Windows XP, Windows Vista, Windows 7,
or Windows 8 on most computers. This
section references all of the mentioned
Windows operating system versions. Differences
between operating systems are pointed out when
appropriate.
Tech Tip