1. BIOS & Operating System
Week 2
BIOS &
Operating System
A+ Guide to Managing and Maintaining your PC, 6e

2. 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.

3. 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

4. Operating Systems Past and Present
What an operating system (OS) does:
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

5. Users and applications depend on the OS to relate to all applications and hardware components

6. 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

7. 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

8. 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

9. Windows 9x/Me is the bridge from DOS to Windows NT

10. 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

11. Windows 2000 Upgrades Windows NT (both desktop and server)
Improvements over Windows NT:
A more stable environment
Support for Plug and Play
Device Manager, Recovery Console
Active Directory
Central security authentication & authorization
Better network support
Features specifically targeting notebook computers.
OS includes only qualified hardware and software.
Windows 2000 is being phased out.

12. 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)

13. 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.

14. 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.

15. Windows 8 Target market is Touch Screen Devices Improved security
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

16. Windows Server 2003 Refers to a suite of Microsoft operating systems:
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

17. UNIX Comprises a class of operating systems
UNIX versions referred to as flavors or distributions
Chief uses:
Controlling networks
Supporting Internet-based applications
Each maker of “Work Stations” had their own UNIX version.
SunOS, Irix (SGI)

18. Linux Variation on UNIX created by Linus Torvalds
OS kernel and source code are freely distributed
Popular distributions:
SuSE (
RedHat (
TurboLinux (
Ubuntu (
Used as both a server and a desktop
X Windows: GUI shells for UNIX and Linux

19. OS/2 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

20. Mac OS 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:
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

21. The Mac OS X desktop is intuitive and easy to use

22. What an Operating System Does
Four functions common to all operating systems:
*** 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.

23. 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

24. Inside an operating system, different components perform various functions

25. 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

26. An OS relates to hardware by way of BIOS and device drivers

27. 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

28. 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.

29. 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

30. Booting a Computer 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
Click Start
Click Turn Off Computer
Click Restart
Some utilities that direct the OS to warmboot.

31. 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.

32. 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

33. Boot Step 1: The ROM BIOS startup program surveys hardware resources and needs and assigns system resources to satisfy those needs

34. Changing the Boot Sequence
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

35. Numbered steps show how BIOS searches for and begins to load an operating system (in this example, Windows NT/2000/XP is the OS)

36. How to Troubleshoot a PC Problem
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

37. Steps to Solving a PC Problem
Key advice:
Ask good questions
Document the process
Four-step problem solving process:
Step 1: Interview the user
Step 2: Back up data
Step 3: Solve the problem
Step 4: Verify the fix and document the solution

38. General approach to troubleshooting

39. Troubleshooting a Failed Boot
It takes time to acquire troubleshooting skills
Hands-on training: troubleshooting a failed boot

40. 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)

41. Use this flowchart when first facing a computer problem

42. 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

43. Beep codes and their meanings

44. 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

45. 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