Week 2
BIOS &
Operating System
A+ Guide to Managing and
Maintaining your PC, 6e
1
Objectives
• Learn how an OS interfaces with users, files and
folders, applications, and hardware
• Learn what happens when you first turn on a PC
before the OS is loaded
• Learn about the Power System.
2
Introduction
• A computer comprises hardware and software
– Physical devices are the visible component
– The controlling software component is not visible
• Computer technicians need to master both parts
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Operating Systems Past and Present
• What an operating system (OS) does:
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Manages hardware
Runs applications
Provides an interface for users
Retrieves and manipulates files
• The OS can be analogized to a “middleman”
• A computer needs only one operating system
• Operating systems have evolved to a complex form
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Users and applications depend on the OS to relate to
all applications and hardware components
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DOS (Disk Operating System)
• The first OS used by IBM computers/compatibles
• Where DOS can still be found:
– Specialized systems using older applications
– On troubleshooting disks or CDs
• Used by some diagnostic applications on UBD_CD
• Windows 3.x and DOS
– Windows 3.x provided a graphical interface
– Underlying OS functions were performed by DOS
• Windows 9x/Me uses DOS in the underlying OS
• Windows XP/2000/Vista/Win7 run DOS emulation
programs
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Figure 2-3 Windows 3.x was layered between DOS
and the user and applications to provide a graphics
interface for the user and a multitasking
environment for applications
A+ Guide to Managing and Maintaining your PC, 6e
7
Windows 9x/Me
• Refers to Windows 95, Windows 98, Windows Me
• Combine a DOS core with graphical user interface
• Designed to bridge legacy and newer technologies
– Backward-compatible with older systems
– Able to accommodate new technologies
• Cautionary note on minimum requirements
– May differ for upgrades and new installations
– May differ for installation and run-time operation
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Windows 9x/Me is the bridge from DOS to Windows NT
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Windows NT
• Two versions of Windows NT (New Technology):
– Windows NT Workstation for desktops
– Windows NT Server to control a network
• Best known feature: new OS core replacing DOS
– First Microsoft product which did not rely on DOS
• Avoid installing Windows NT
– Windows NT introduced many new problems
• Security
• Compatibility to most gaming s/w
– Did not support Direct x
– Problems only solved in later versions of Windows
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Windows 2000
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Upgrades Windows NT (both desktop and server)
Improvements over Windows NT:
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A more stable environment
Support for Plug and Play
Device Manager, Recovery Console
Active Directory
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Central security authentication & authorization
– Better network support
– Features specifically targeting notebook computers.
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OS includes only qualified hardware and software.
Windows 2000 is being phased out.
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Windows XP
• Integrates Windows 9x/Me and Windows 2000
• Two main versions: Home Edition and Professional
• Noteworthy new features:
– Allows two users to logon and open applications
– Incorporates Windows Messenger and Media Player
– Adds advanced security, such as Windows Firewall
• Hardware requirements
– 64 MB RAM (128 MB recommended)
– 1.5 GB free hard drive space (2 GB recommended)
• Typical installs consume 3+ GB
– 233-MHz CPU speed (300-MHz recommended)
12
Windows Vista
• Next generation of Windows operating systems
• Noteworthy new features:
– New graphical interface
• Harder to use?
• Targeted a less computer literate user
– Supported a consumer electronic paradigm
– Revamped engine
• Faster
• Too security conscious for typical users.
– A new interface between it and applications.
• Some s/w must be upgraded.
– Many hidden “features”.
– Driver compatibility issues.
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Windows 7
• Basically an updated Vista without the problems of Vista
• Features
– Performance enhancements.
– Better support for touch screens
• Better handwriting & speech recognition
– More user centric, users have more control over the look and
feel as well as performance tweeks
– Many backward compatible look and feel enhancements which
vista had are now a free download from MS, e.g. classic menu.
• H/W resources
– 32 bit, same as vista
– 64 bit, considerably more, almost double.
– 2Gb ram min, 20 Gb hd space min.
Windows 8
• Target market is Touch Screen Devices
– Use of ribbon interface
• Improved security
– Pins & picture passwords
• Improved performance
– USB 3.0 support
• Boot speed increased by hibernating the Kernel.
• Can be compiled for Intel and Arm processors
– Arm used in many hand held devices
– Cell phones
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Windows 10
• More traditional UI.
– Auto detects desktop or touch and defaults correct
interface.
• Unified across all platforms, PC, Cell, Xbox
– It’s free
• Less Storage required, better system restore.
• Better virtualization
– Ability to install other OS in a virtual space under
W10.
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Windows Server 2003
• Refers to a suite of Microsoft operating systems:
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Windows Small Business Server 2003
Storage Server 2003
Server 2003 Web Edition
Server 2003 Standard Edition
Server 2003 Enterprise Edition
Server 2003 Datacenter Edition
• Not designed for use in a PC
• Not covered in this text
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UNIX
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Comprises a class of operating systems
UNIX versions referred to as flavors or distributions
Chief uses:
– Controlling networks
– Supporting Internet-based applications
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Each maker of “Work Stations” had their own UNIX
version.
– Derived from Bell Labs and AT&T
– SunOS, Irix (SGI)
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Linux
• Variation on UNIX created by Linus Torvalds.
– Not Unix but a look alike.
• OS kernel and source code are freely distributed
• Popular distributions:
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SuSE (www.novell.com/linux/suse)
RedHat (www.redhat.com)
TurboLinux (www.turbolinux.com)
Ubuntu (www.ubuntu.com)
• Used as both a server and a desktop
• X Windows: GUI shells for UNIX and Linux
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FreeBSD
• Berkley Software Distribution
– Free
– Derived directly from Bell Labs and AT&T to run on a
PC
– Unlike Linux, it maintains many of the security and
performance features of UNIX.
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OS/2
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Jointly developed by IBM and Microsoft
Chiefly used in certain types of networks
Part of OS/2 was incorporated into Windows NT
OS/2 is not covered in this book
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Mac OS
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First introduced in 1984 with Macintosh computers
Current version: Mac OS X (10.10)
Mac OS X can work on most Intel-based computers
Markets: education, desktop publishing, graphics
Noteworthy features:
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Support for graphics and multimedia capabilities
Use of the Finder program to provide the desktop
Superior Plug and Play capabilities
Excellent support for multitasking
Unix based kernel with Mac interface
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The Mac OS X desktop is intuitive and easy to use
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What an Operating System Does
• Four functions common to all operating systems:
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*** Providing a user interface
Managing files
Managing applications
*** Managing hardware
• All OSs can have similar core components.
• All do the same job
– Some better then others.
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Operating System Components
• Components common to all OSs: shell and kernel
• The shell exposes functions to users and applications
– Example 1: enables user to select a CD
– Example 2: enables application to print a document
• The kernel (core) interacts with hardware devices
– Example: passes a print request to a printer device
• Registry database and initialization files
– Used to store configuration information in Windows
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Inside an operating system, different components
perform various functions
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An OS Manages Hardware
• OS interacts with hardware using drivers or BIOS
• Software falls into three categories:
– Device drivers, Main BIOS or component BIOS
– Operating system
– Application software
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An OS relates to hardware by way of BIOS and device drivers
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How an OS Uses Device Drivers to
Manage Devices
• Device drivers: specify how to interact with a device
– Example: a driver links a computer to a digital camera
• Drivers are provided by OS and device manufacturer
• Device drivers in Windows
– Before installation, verify Microsoft has tested device
– Registry stores information about 32/64-bit device
drivers
– Updated drivers are available at manufacturer’s site
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How an OS Uses System BIOS to Manage
Devices
• System BIOS contains device information
– Instructions enable CPU to communicate with device
– Example: keyboard activated at startup using BIOS
• Configure BIOS device interaction in CMOS setup
• The OS may use system BIOS to access devices
• Disadvantage of using BIOS device management
– BIOS does not operate as fast as device drivers
• Device drivers are faster
– Reside in Memory
– BIOS is Firmware, which is slow.
• Maybe limited in functionality.
• Supports only basic operations.
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Understanding the Boot Process
• Key learning objectives
– Know how to boot a PC
– Understand what happens first when a PC is turned on
– Understand how an operating system is loaded
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Booting a Computer
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Process that drives a computer to a working state
Hard (cold) boot: turn the power switch on
Soft (warm) boot: allow the OS to reboot
How to soft boot Windows XP .. Win 8
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Click Start
Click Turn Off Computer
Click Restart
Some utilities that direct the OS to warmboot.
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Choosing Between a Hard Boot and a
Soft Boot
• Hard boots are more stressful on machines
– Power surges through system when PC is turned on
• Reasons to choose a soft boot over hard boot
– Less stressful on the machine
– Faster due to skipping initial steps
• Some computers have a soft and hard power switch
– Soft power switch shuts down and restarts Windows
– Hard power switch cuts power and restarts machine
• Dell power button, will soft boot if pressed.
– Shut down machine if held for 5 sec.
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The Startup BIOS Controls the
Beginning of the Boot
• The startup BIOS gets a system up and running
• Four phases of the boot process:
– BIOS runs the POST and assigns system resources
• POST: power-on self test
– BIOS searches for and loads an OS
– OS configures system and completes its own loading
– Application software is loaded and executed
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Boot Step 1: The ROM BIOS startup program surveys
hardware resources and needs and assigns system
resources to satisfy those needs
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Changing the Boot Sequence
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BIOS looks to CMOS RAM to locate the OS
Boot sequence: order of drives checked for an OS
Change boot sequence using CMOS setup utilities
Access CMOS setup utilities when PC is turned on
– Example: press F8 before Windows screen appears
36
Numbered steps show how BIOS searches for and begins to load an
operating system (in this example, Windows NT/2000/XP is the OS)
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How to Troubleshoot a PC Problem
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Assume the attitude of an investigator
Do not compound the problem by your own actions
Look at the problem as a learning opportunity
Ask questions until you understand the problem
Believe that you can solve the problem
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Steps to Solving a PC Problem
• Key advice:
– Ask good questions
– Document the process
• Four-step problem solving process:
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Step 1: Interview the user
Step 2: Back up data
Step 3: Solve the problem
Step 4: Verify the fix and document the solution
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General approach to troubleshooting
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Troubleshooting a Failed Boot
• It takes time to acquire troubleshooting skills
• Hands-on training: troubleshooting a failed boot
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My Computer Won’t Boot
• First step: maintain your calm
• Second step: develop a game plan
• Figure 3-45 provides a procedure
– Plan is driven by a set of yes-no questions
– Example: Does the PC boot properly?
• If no, troubleshooter is directed to another question
• If yes, troubleshooter is directed to stop (for now)
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Use this flowchart when first facing a computer problem
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Troubleshooting Major Subsystems
Used For Booting
• Categories of troubleshooting steps in Figure 3-45
– The electrical subsystem
– Essential hardware devices
• The motherboard, memory, and the CPU
– Video
– Reading from the hard drive
• Key aides: tables identifying error codes
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Beep codes and their meanings
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Summary
• Some PC repair tools: recovery CDs, screwdrivers,
POST, cleaning pads and solutions, diagnostic cards
• Preventive maintenance plans extend the life of a PC
• Follow an organization’s preventive maintenance
plan, or develop one if it does not exist
• Computers present chemical and electrical hazards
• Protect components in case from ESD by grounding
yourself and the PC
46
Summary (continued)
• Assembling and reassembling a PC prepares the
technician for actual repair work
• Startup BIOS controls when the boot process begins
• Four step boot process: POST, loading the OS, OS
initializing itself, loading and executing applications
• Expert troubleshooters ask good questions
• Before tackling a problem, develop a game plan
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