Session 2: Introduction to Windows pot

Introduction to Operating Systems“An operating system is a program that acts as an interface between the user and the computer hardware and controls the execution of all kinds of program

Introduction to Windows

Session 2

Session Objectives

Explain the concept of an Operating System Explain the concept of Networking

Explain workgroup and domain models

Identify features of Windows Operating System family

Define some commonly used terminology

Explain concept of sharing in Windows

Introduction to Operating Systems

“An operating system is a program that acts as an interface between the user and the computer hardware and controls the execution of all kinds of programs.”

THE USER

Floppy disk Hard disk

Output device Printer / Monitor

THE OPERATING SYSTEM

M E M O R Y

The Control Unit / The ALU

Central Processing Unit

Input device Keyboard

Functions of an Operating System

It loads itself into memory.

It loads user program into memory.

It loads required data into memory.

It interprets program instructions.

Gives instruction to display results on screen.

It manages resources.

Single-user system

Has a single CPU and one set of I/O devices Popular example - Microsoft Disk Operating system or MS-DOS.

Multi-user systems

More than one user can work on system

Each user could be working on different set of

programs and data

Central computer acts as server

Data and programs stored on server

All processing is done by server

Computers connected as nodes or workstations function as dumb terminals or intelligent terminalsCommon multi-user system is UNIX

Introduction to Networking

“A computer network is a data communication network wherein two or more computers and peripheral devices are linked together”

Connection may be permanent (where cables are used) or temporary (through phone lines)

Various devices are connected through network interface card (NIC)

Illustration of a Computer Network

= Communication network node Communications network

Uses of Networking

Centralised storage

Sharing data and resources

Remote database and program access

Communication

Economical

Workgroups and Domains

In Windows NT two prevalent modes of grouping networked computers:

– Workgroups

– Domains

Workgroup Model

Networked computers grouped physically or logically.One or more of computers - shared resources

Computers share peer-to-peer relationship

Local account database

Resources / administration distributed throughout computers on workgroup

Workgroup Model (contd.)

Advantages

– Simple design makes it easy to implement

– Easy to share resources

– Convenient for a limited number of users

Domain Model

Networked computers are grouped logically

One or more computer (s) having shared resources Centralised domain directory database contains user accounts and security information of all users in that domain

All computers in domain share this database

Domain Model (contd.)

One of the computers is configured as central server

or primary domain controller (PDC)

The PDC maintains the centralised domain directory database

Typically an additional server is connected which acts

as backup domain controller (BDC)

Domain Model (contd.)

Advantages

– Centralised administration

– Security management is centralised

Disadvantages

– Administration is more complex

– Sharing resources is more complex

The World of Windows

Command line interface, users have to know relevant DOS commands.

Windows - graphical user interface (GUI)

Initial versions of Windows rode on top of DOS (Disk Operating System)

Windows 4.0 family of operating systems combines operating system technology of DOS and graphical user interface of earlier

Windows Operating System

Windows Operating System family

(contd.)

Similarities

– common user interface

– features and utilities

– 32-bit operating systems

Windows 2000 Professional makes it easier to:

– Work with files

– Find information

– Personalize your computing environment

– Work on the Web

– Work remotely

streamlined with Windows 2000 Professional.

With Windows 2000, your workstation will be easier to:

– Set up

– Administer

– Support

Windows 2000 also provides:

– Improved driver support

– Increased support for new-generation

hardware and multimedia technologies

Features of Windows 2000

Professional(contd.)

More powerful

For all your computing needs,

Windows 2000 Professional provides:

– Industrial-strength reliability

– The highest level of security

– Powerful performance.

Definitions (contd.)

Mapped drive – a mapped drive hard disk on another computer that user can access as their own It appears as a letter on user’s computer

Permissions

Remote access

Concept of Ownership

Creator of file or folder - owner of file or folder

Owner decides access

Done through process of sharing and granting permissions

By default, administrator has permission to use object

Controlled by removing permission

Administrator can forcibly “take ownership” of object

Sharing on the network

Depends on permissions you are assigned

– Read permission - view contents of folder

– Print permission - send print jobs, user cannot manage jobs of other users

Types of Permissions

Shared folder permissions

NTFS (NT File System) permissions

Shared folder permissions

When folder is shared, permitted users gain access

to all files in folder

No individual file level control

No security when a user logs on locally

After folder is shared appropriate shared folder permission can be assigned to required users

Shared permissions only way to secure resources in

a FAT file system

Shared Folder permission types

No Access

Read

Change

Full Control

Shared folder permissions

Permissions on shared folder flow down to folders

sub-Shared permissions can be applied to both FAT and NTFS partitions

Drawbacks :

– Shared permissions do not provide adequate security

– Shared permissions can be applied only to folders

– Shared permissions are effective only over network.

NTFS Permissions

NTFS permission can be assigned only on partition formatted using NTFS file system

Advantages:

– NTFS permission applied to files and folders

– NTFS permissions applicable even on local computer

NTFS Permission Types

When applied to folders

Read

– Display folder names / display attributes

– Display owner name and permissions

Write

– Add files and folders

– Change folder attributes

– Display owner name and permission

NTFS Permission Types

(contd.)

eXecute

– Display folder attributes / Perform changes to

subfolders / Display owner name and permissionDelete

NTFS Permission Types

When applied to files

Read

– Display file data / Display attributes

– Display owner name and permission

Write

– Change file attributes / Create data in files

– Append data to files / Display owner name and permissions

NTFS Permission Types (contd.)

When applied to files

eXecute

– Display file attribute / Run a file if executable

– Display owner name and permission

Access Permissions for files

Standard Permissions Individual Permissions