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Chapter 7
Windows NT/2000/XP
Operating Systems
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File Systems
•The main purpose of the file system is to store and retrieve data
from the computer hard disk. How the data is organized,
optimized, and retrieved comes from the file system on the hard
drive.
•There are three different file systems available in the Windows
Operating System Environment: FAT16, FAT32, and NTFS.
•When using Windows NT, 2000, or XP, the best file system to
use would be NTFS.
•Both FAT16 and FAT32 file systems maintain two copies of the
FAT (the default and backup copy), but only FAT32 can use the
backup copy as well as the default copy.
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FAT16
•The 16-bit FAT (FAT16) is used for most hard drives with DOS,
Windows 3.1, and the first version of Windows 95.
•It limits the file names to eight characters with a three-letter
extension.
•The FAT16 file system can only recognize partitions up to 2 GB
in size.
•In the FAT16 file system, the root directory can be located only
at the beginning of the hard disk. This poses problems if this part
of the hard disk becomes damaged.
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FAT16
•The FAT structure also maintains a set of attributes for each file.
•S which stands for a system dataset
•H which means that the file is hidden in the directory display
•A which means that the file will be archived the next time the
disk is backed up
•R which will make the file Read-Only.
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FAT32
•FAT32 is still based on the original FAT system and works in a
similar fashion in order to remain compatible with existing
programs, networks, and device drivers.
•The FAT32 file system was designed to support hard drives up
to 2048 GB.
•FAT32 file system, the root directory can be located anywhere
on the hard disk. This is very useful because if the section of the
hard disk containing the root directory were to become damaged
now, the root directory could be moved to another section of the
hard disk and the damaged portion of the hard disk could be
repaired.
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NTFS
•The Windows NT File System (NTFS) supports all Windows
NT/2000/XP operating systems.
•NTFS5 (the latest version) also includes a feature called disk
quotas, which provide the system administrator with the ability to
assign limits to the amount of hard disk space that users are
allowed to occupy on the server or workstation.
•NTFS file system provides support for added features like file
and directory security by using Discretionary Access Control Lists
(DACL) and System Access Control Lists (SACL).
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NTFS
•The Windows NT/2000/XP operating systems were designed to
appeal to the corporate and business market.
•If the system crashes, NTFS can examine the log file and use it
to restore the disk to a consistent state with minimal data loss.
This feature is called Fault Tolerance.
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High Performance File System
•HPFS) is a seldom used and much more obscure type of file
system but it is worth mentioning only because the OS/2
software that uses this file system is still in use today. Microsoft
did use this file system with its Windows 3.51 operating system.
•The HPFS file system directory structure was the same as the
FAT file system but allowed long file names of up to 254
characters.
•Another aspect of HPFS was its ability to map hard disks up to 8
GB instead of 2 GB.
•Instead of clusters as the unit of management on the hard disk,
HPFS used physical sectors.
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Sectors and Clusters
•The hard disk is divided into 512-byte pieces called sectors.
•The sectors are then grouped into larger pieces called clusters.
Each cluster can hold only one file.
•The size of the clusters is determined by the size of the
partitions made on the hard disk.
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NTFS Security and Permissions
•Windows NT/2000/XP has enhanced system security features
like file encryption and the ability to set permissions on files as
well as directories or folders.
•File and directory permissions are used to specify which users
and groups can gain access to files and folders and what they
can do with the contents of the file or folder.
•Another security feature included with the Windows 2000/XP
operating systems, provided NTFS is used, is encryption.
•These features are only available in the Windows NT/2000/XP
operating systems if NTFS is used and not the FAT file system.
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Folder Permissions
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File Permissions
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Encryption
•Microsoft provides a specific file system for encryption called the
Encrypting File System (EFS).
•This provides administrators with the means to apply encryption
to a file or folder that only the person who encrypted the file can
view.
•The administrator can specify the users who can view the file as
well. Users can be granted access to the file if they are assigned
a public key.
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Windows 2000 Boot Process
•The Boot Process of the Windows 2000 operating system is
very different from Windows 9x. The Windows 9x boot process is
much simpler and straightforward.
•The Windows 2000 boot process occurs in five stages:
•The preboot sequence
•The boot sequence
•The kernel load
•The kernel initialization
•The logon process
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Preboot Process
•The first step in the Boot Process after the power is turned on to
the computer is the Power On Self Test (POST).
•After the POST routine is complete, the computer will locate a
boot device, and load the Master Boot Record (MBR) into
memory, which in turn locates the active partition and loads it into
memory.
•The MBR allows programs such as the Disk Operating System
to load into RAM.
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Boot Sequence
•The boot sequence begins to gather information about hardware
and drivers. NTLDR is the key component of this step. NTLDR
uses the following files: Ntdetect.com, Boot.ini, and Bootsect.dos
(The Bootsect.dos file will only be used in the event that the
computer is set up to dual-boot.)
•The Boot.ini file enables the display of the boot menu on the
screen.
•Ntdetect.com will detect hardware
•Once Ntdetect.com has collected the hardware information,
NTLDR will load Ntoskrnl.exe and pass that information.
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Kernal Load
•The Kernel Load phase begins with Ntoskrnl.exe loading along
with the Hal.dll file.
Kernal Initialization
•This simply means that it is recognizing everything that was
loaded previously so that NTLDR can now give control to the
operating system kernel.
•The operating system can now begin the final stages of loading.
•The Graphical User Interface (GUI) is now seen and it will show
a status bar indicating that the GUI is now loading.
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Logon
•The Logon screen begins the final step in the boot-up process.
•Although this is the final step, it is not considered a completed or
successful boot until a user logs on.
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Device Drivers
•Device drivers are programs that basically tell the operating
system how to control specific devices.
•They act as an interface between the operating system and the
device, which allows them to recognize and communicate with
each other.
•The ability to add many devices to modern computers to expand
their capabilities has become increasingly easier with the
advances made in Plug-and-play Technology.
•The goal of Plug-and-play is to create a computer whose
hardware and software work together to automatically configure
devices and assign resources.
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Administrative Tools
•The Administrative Tools utility is a powerful Windows
NT/2000/XP System Tool that enables the administrator to
control just about everything related to the local computer.
•From this utility, permission to log on to the computer can be
controlled by creating Local User accounts.
•The Disk Management utility allows the administrator to control
and manipulate the computer hard drives.
•There is also a Services tab that can start or stop any of the
programs that are running on the computer.
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Disk Types
•There are two types of disks that are available in Windows 2000
and XP, basic disks and dynamic disks.
•Basic Disk storage is typically referred to as the industry
standard and is identified by a hard drive that is divided into
partitions.
•When using Dynamic Disk Storage, multidisk volumes are
referred to as hard disk space. This is because the hard drives
are no longer dealt with as if they were one complete disk divided
by partitions, but rather as multidisk volumes.
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Dynamic Disk Volumes
•The three types of volumes that can be created with
Windows 2000 professional are simple, striped, and
spanned volumes.
• Simple Volume – Acts as a basic disk that will
contain disk space from a complete single disk and is
not fault tolerant.
• Spanned Volume – This volume will include disk
space from multiple disks. There can be up to 32
disks in a spanned volume.
• Striped Volume – Also known as RAID-0, a stripped
volume combines areas of free space from multiple
hard disks, up to 32, into one logical volume.
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Dynamic Disk Volumes
• Mirrored and RAID-5 volumes are types of volumes that can
only be created with the Windows 2000 Server operating
system.
• Mirrored volumes provide fault tolerance. It contains two
identical copies of a simple volume that stores the same
data on two separate hard drives.
• RAID-5 Volume - in the event that one of the drives should
fail, the remaining two disks recreate the data automatically
without having to shut down the server.
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