Understanding Windows

1. Understanding Windows Chapter 12

2. Overview • In this chapter, you will learn to • Identify and explain the basic functions of an operating system • Identify the features and characteristics common to all Windows PCs • Identify and differentiate the features an characteristics of Windows 9x/Me • Identify and differentiate the features an characteristics of Windows NT/2000/XP

3. Functions of the Operating System

4. Functions of an Operating System • Communicate with hardware • Provide a user interface • Provide a structure for access to applications • Enable users to manipulate programs and data

5. Operating System Traits • An OS works only with a particular type of processor • An OS begins running as soon as the PC finishes its POST • Application programs cannot run on a PC without an OS • The OS provides a set of application programming interfaces (APIs) • An OS must be able to use new software and hardware

6. Communicating with Hardware • The system BIOS is programming code that tells the computer how to talk to basic hardware • The OS works with the BIOS to talk to these devices • When the BIOS does not know how to talk to a piece of hardware, the OS talks directly to the device • Most OS’s use device drivers provided by the manufacturer (Bring Your Own BIOS) to interpret the language necessary to talk to a new device • When there’s a problem, the OS should provide error handling or at least error notification

7. Creating a User Interface • A user interface needs to • Show what applications are available • Provide an easy way to access those applications • Provide a way to label and save the data generated using the application • When a program starts, the user interface must disappear and allow the application to take over the screen • While the application is running, the OS must provide access to hardware as needed • When the application is shut down, the OS must return the user to the user interface

8. Organizing Programs and Data • The OS must be able to organize programs and data • What is data and how can we distinguish between different types of data? • What are programs and what type of program is it? • How can I distinguish the various places to store the data or programs? • How can I efficiently retrieve the data or program?

9. Command Line Character-based or text-based Disk Operating System (DOS) Single-tasking DOS consists of IO.SYS MSDOS.SYS COMMAND.COM DOS configuration files CONFIG.SYS AUTOEXEC.BAT Graphical User Interface (GUI) Not necessarily the OS Win95, Win98, Win31 ran on top of DOS Apple’s OS 9 and OS X operate only as a GUI WinNT, Win2K, WinXP are GUI operating systems with a command line built in Operating System Implementations

11. Common Windows Features and Characteristics

12. User Interface • Login • Every version of Windows supports multiple users • Requiring a user login increases security • Desktop • Primary interface to the computer • Taskbar and Start Menu • Runs along the bottom of the desktop and includes up to four sections • Start menu allows access the installed programs • System tray shows programs running in the background • Quick Launch enables you to launch often-used programs with a single click

13. User Interface • My Computer • Provides access to drives, folders, and files • Customizable: may display different views, show hidden files, hide file extensions, and more • Windows Explorer • Another utility for accessing drives, folders, and files • My Documents • My Pictures, My Music, My Videos

14. User Interface • Recycle Bin • When you delete files they are sent to the Recycle Bin, a special folder just in case you change your mind • Network Neighborhood or My Network Places • Shows the current network connections available to you

15. Tech Utilities: Control Panel • Maintenance, upgrade, and configuration aspects of Windows • StartSettingsControl Panel • Contains programs, called applets • Any icon in the Control Panel is a file with a CPL extension • If Control Panel won’t start, one of these is probably corrupt – rename each one until you find the bad one • Each applet displays text that helps to explain its functions

16. Tech Utilities: Control Panel

17. Tech Utilities: Device Manager • Device Manager is a primary tool for dealing with devices and device drivers in Windows • A red “x” or a yellow exclamation point is displayed, if Windows detects a problem • Devices are organized in special groups called types • Access thru the System applet in Control Panel

18. Tech Utilities: System Tools • System Tools is a collection of tech utilities found on the Start menu • Start  Programs Accessories System Tools

19. Tech Utilities: Command Line • Command Line • Start  Run command • Windows 2000/XP offer you a more powerful command line: Start Run cmd

20. Tech Utilities: MMC • Microsoft Management Console (MMC) • A shell program that holds individual utilities called snap-ins • Start  Run  mmc • You start with a blank console and then add snap-ins – then save the new customized console you created • File  Add/Remove Snap-ins Add

21. Tech Utilities: Adminstrative Tools • Administrative Tools • A folder that holds many pre-defined MMC consoles built by Microsoft • Go to Control Panel and click on Administrative Tools • The three most used Administrative Tools are • Computer Management • Event Viewer • Performance

22. Tech Utilities: Computer Management • Computer Management • A pre-defined MMC that pulls together snap-ins related to many computer management options

23. Tech Utilities: Event Viewer • Event Viewer • Keeps track of events that happen with your computer

24. Tech Utilities: Performance • Performance • System Monitor may show real time data • Performance Logs and Alerts

25. Services • Services • Separate programs that handle a lot of functions for Windows • Found in Administrative Tools • Double-click on any service to examine its properties and settings • Services start automatically, manually, or may be disabled

26. System Folder • System Folder • Folder where the OS files were installed • %systemroot% • %windir% for Win9x

27. What is the Registry? • Registry • A unified database where Windows stores all hardware and software configuration information for the local computer • Hardware, central processor, keyboard, mouse, etc. • Device drivers • Applications • Network protocols • NIC settings • User account information like group membership, rights and permissions

28. Registry Editors • Regedit • Clearly better in key searching down to the value of the keys • Used by Windows 9x/Me • Also installed in Windows NT/2000/XP • Regedt32 • Used by Windows NT/2000/XP Better for adding keys and modifying their values • Searches only down to keys and subkeys – not values • When using the Registry Editors, be very careful! • Does not recognize syntax or semantic errors • May prevent your operating system from loading

29. REGEDIT

30. REGEDT32

31. Registry • The Registry has six main groups , or root keys shown below HKEY_DYN_DATA is used in Windows 9x – not 2000 or XP

32. HKEY_LOCAL_MACHINE • Configuration data about local computer • Used by applications, device drivers and Windows • Determines which device drivers and services load during startup • Same regardless of user

33. HKEY_USERS • Stores all the personalization information for all users on the PC • Subkeys are: • DEFAULT subkey • System default profile used when Ctrl+Alt+Del logon screen is displayed • Security identifier (SID) of user currently logged on the computer

34. HKEY_CURRENT_USER • Data about user currently logged on interactively • Copy stored for each user account that has ever logged on to the computer in systemroot\Profiles\user_name in Ntuser.dat • Points to same data as under HKEY_USERS\SID_of_the_currently_logged_on_ user • Takes precedence over duplicate settings in HKEY_LOCAL_MACHINE

35. HKEY_CLASSES_ROOT • Information about file associations and data associated with COM objects (Component Object Model – OLE) • Points to CLASSES subkey under HKEY_LOCAL_MACHINE\SOFTWARE

36. HKEY_CURRENT_CONFIG • Data about active hardware profile • Extracted from SOFTWARE and SYSTEM keys of HKEY_LOCAL_MACHINE

37. Virtual Memory • All versions of Windows use virtual memory • Windows swap files are used to implement virtual memory • Windows sets the initial size of the swap file automatically according to the free space available on the C: drive • The swap file in Windows 9x is called WIN386.SWP; it is known as PAGEFILE.SYS in Windows 2000

38. Virtual Memory • When you need to run another program but your RAM is filled up, Windows will offload something that hasn’t been used recently from RAM to the hard drive into a swap file to make room • If you need to access the data that was offloaded into RAM, Windows will retrieve it from the hard drive

39. Essential Windows • You should already have basic user skills in Windows. As a review check out Essential Windows on line at www.totalsem.com

40. Features and Characteristics of Windows 9x/Me

41. Windows • Windows 3.1 was a graphical shell that ran on top of DOS • Microsoft debuted Windows 95 as its first standalone GUI operating system • Windows 9x and Me followed in later years • Many files and configuration utilities were held over from earlier OSs

42. The Windows Boot Process • Windows 9x is a combination of the DOS protected-mode interface (DPMI) and a protected-mode GUI • Windows 9x first starts the DOS aspect of Windows and then the GUI • Booting Windows 9x without the GUI from the boot menu is different than running a DOS window inside Windows 9x

43. FAT32 • Later versions of Windows 95 and all versions of Windows that followed support the FAT32 file format • Partitions up to 2 terabytes in size

44. Long Filenames • Windows 9x/Me • Allows long file names up to 255 characters in length • Removed the old 8.3 filename limitation of DOS • Adopted the 16-bit unicode character set • Unicode supports 65,536 characters • ASCII used by DOS was 8-bits and supported only 256 characters

45. DPMI Core Files • IO.SYS • Combined the previous IO.SYS and MSDOS.SYS into IO.SYS • MSDOS.SYS • Used as a startup options file – read-only, hidden text file in root directory • COMMAND.COM • Not needed if the system will always run in the GUI mode

46. Boot Menu Press F8 (or the left Ctrl key in Windows 98) when “Starting Windows..” appears to access the Boot Menu

47. Boot Menu • Normal • Logged • Creates a bootlog.txt file detailing the boot up process • Safe mode • Only the OS, mouse, keyboard, and VGA video drivers are loaded • Useful when Windows won’t boot due to a bad driver • Safe mode with network support • Step-by-step confirmation

48. Boot Menu • Command prompt only • Does everything but start the GUI • Just type win to start Windows • Safe mode command prompt only • Skips all startup files • Must reboot to start Windows • Previous version of MS-DOS • Useful only if you installed Windows over a true DOS system

49. MSDOS.SYS • MSDOS.SYS • Hidden, read-only text file that replaces many of the CONFIG.SYS and AUTOEXEC.BAT functions • Edit using any text editor (after unchecking its attributes) • Organized like an INI file with groups and options under each setting • There are many useful options in the [Options] group – see pages 429-430 in the book for a listing

50. Configuration Files • Windows 9x/Me will use CONFIG.SYS and AUTOEXEC.BAT to load legacy device drivers and terminate and stay resident (TSR) programs