Operating System and Utility Programs

System Software and Operating System Functions

  • System software consists of programs that control or maintain the operations of the computer and its devices.

  • There are two primary types of system software:

    • Operating systems

    • Utility programs

  • An operating system (OS) is a set of programs containing instructions that work together to coordinate all activities among computer hardware resources. The core functions provided by an OS include:

    • Starting and shutting down the computer

    • Providing a user interface

    • Managing programs and memory

    • Coordinating tasks and configuring devices

    • Establishing Internet connections

    • Monitoring performance and providing file management utilities

    • Automatic updating

    • Controlling networks and administering security

The Computer Startup and Shutdown Process

  • Booting is the process of starting or restarting a computer.

    • Cold Boot: Turning on a computer that has been powered off completely.

    • Warm Boot: Using the operating system to restart a computer while it is still powered on.

  • A boot drive is the specific drive from which a computer starts. Computers can also start from a boot disk. A recovery disk contains a few specific system files that will allow the computer to start if the primary drive fails.

  • The steps of the PC booting process are as follows:

    • Step 11: The power supply sends a signal to the components in the system unit.

    • Step 22: The processor finds the ROM chip(s) containing the BIOS (Basic Input/Output System).

    • Step 33: The BIOS performs the POST (Power-On Self Test), which checks hardware components such as the mouse, keyboard, and adapter cards.

    • Step 44: The results of the POST are compared with data stored in a CMOS chip.

    • Step 55: The BIOS searches for system files on a USB flash drive, an optical disc drive, or directly on drive C (the hard disk).

    • Step 66: The operating system's system files and the kernel load into memory (RAM) from storage.

    • Step 77: The OS loads configuration information, requests user information if necessary, starts background processes, and displays the desktop.

  • Operating systems include specific shutdown options:

    • Sleep mode: Saves open documents and programs to RAM, turns off unneeded functions, and places the computer in a low-power state.

    • Hibernate: Saves open documents and programs to a hard disk before removing power from the computer.

User Interface and Program Coordination

  • A user interface controls how data and instructions are entered and how information is displayed.

    • Graphical User Interface (GUI): Interaction occurs through menus and visual images.

    • Command-line Interface: The user uses a keyboard to enter specific data and instructions at a prompt.

  • Operating systems handle programs in ways that directly affect productivity:

    • Single user vs. Multiuser

    • Single tasking vs. Multitasking

    • Foreground vs. Background: The foreground program is the one currently in use; other programs run in the background.

    • Preemptive multitasking and Multiprocessing.

Hardware, Performance, and Network Management

  • Memory Management: Optimizes the use of RAM. Virtual memory is a portion of a storage medium functioning as additional RAM when physical RAM is insufficient.

  • Task Coordination: The OS determines the order in which tasks are processed. For example, spooling manages the print queue by holding documents to be printed in a buffer on the disk until the printer is ready.

  • Drivers: A driver is a small program that tells the OS how to communicate with a specific device. Plug and Play technology automatically configures new devices as they are installed.

  • Performance Monitor: A program that assesses and reports information regarding computer resources and devices.

  • Network Administration: A server operating system organizes and coordinates how multiple users access and share network resources. A network administrator uses the OS to:

    • Add and remove users, computers, and devices.

    • Install software.

    • Administer network security.

    • Manage user accounts, including user names (User ID) and private passwords.

Classifications and Types of Operating Systems

  • Stand-alone Operating Systems: Complete systems that work on desktops, notebooks, or mobile devices. Examples include:

    • DOS

    • Early Windows (e.g., Windows 3.x3.x, Windows 9595, Windows NT Workstation, Windows 9898, Windows 20002000 Professional, Windows Millennium Edition, Windows XP, Windows Vista)

    • Windows 77

    • Mac OS X

    • UNIX and Linux

  • Server Operating Systems: Designed to support networks. Examples include:

    • Early Windows Server (Windows NT Server, Windows 20002000 Server, Windows Server 20032003)

    • Windows Server 20082008

    • UNIX and Linux

    • Solaris

    • NetWare

  • Embedded Operating Systems: Reside on a ROM chip in mobile or consumer electronic devices. Examples include:

    • Windows Embedded CE

    • Windows Phone 77

    • Palm OS

    • iPhone OS

    • BlackBerry

    • Google Android

    • Embedded Linux

    • Symbian OS

Windows 7 Features and Performance

  • Windows 77 Editions: Starter, Home Premium, Professional, and Ultimate.

  • Built-in Programs: Windows Firewall, Windows DVD Maker, Windows Media Player, and Desktop Gallery.

  • Reliability and Performance:

    • Low-powered Sleep state for quick resumption.

    • Windows SuperFetch technology for faster program starts.

    • Built-in hardware diagnostics and automatic recovery from failures.

  • Security and Information Management:

    • User Account Control for permission restriction.

    • Improved firewall and Windows Defender.

    • Parental controls for monitoring usage.

    • Search functionality based on file names or properties.

    • Snipping Tool and Windows Calendar.

  • Appearance and Navigation:

    • Translucent windows and window previews on the taskbar.

    • Windows Snap and Aero Shake for window management.

    • Jump Lists for quick access to recent files.

    • Windows Touch for multi-touch support.

  • Communications and Internet:

    • Enhanced Internet Explorer.

    • Windows Live Essentials: Includes Messenger, Photo Gallery, Mail, Writer, and Movie Maker.

    • Speech recognition for voice interaction.

Essential System Utility Programs

  • File Manager: Performs functions like displaying files, organizing folders, copying, renaming, deleting, moving, and creating shortcuts.

  • Search Utility: Locates files based on specified criteria.

  • Image Viewer: Displays, copies, and prints graphics file contents.

  • Uninstaller: Removes a program and its associated system file entries.

  • Disk Cleanup: Searches for and removes unnecessary files such as temporary internet files, downloaded program files, and unused files.

  • Disk Defragmenter: Reorganizes files and unused space on a hard disk so programs run faster.

  • Backup and Restore Utilities: Backup copies files to another medium; Restore returns them to their original form.

  • Screen Saver: Displays moving images or a blank screen after a period of inactivity.

  • Personal Firewall: Detects and protects against unauthorized intrusions.

Computer Security, Viruses, and Content Filtering

  • Malware Definitions:

    • Virus: A potentially damaging program that affects a computer negatively.

    • Worm: Copies itself repeatedly in memory or over a network.

    • Trojan Horse: Hides within or looks like a legitimate program.

    • Antivirus Program: Protects against viruses.

  • Signs of Virus Infection:

    • Unusual messages, images, or sounds.

    • Less available memory than expected.

    • Missing, corrupted, or mysteriously appearing files.

    • Changes in file size or system properties.

    • Significantly slower performance.

  • Privacy and Advertising Software:

    • Spyware: Secretly collects information about a user.

    • Adware: Displays online advertisements in banners or pop-ups.

    • Removers: Specific programs designed to delete spyware and adware.

  • Filters: Programs used to remove or block items from display, including web filtering software, anti-spam programs, phishing filters, and pop-up blockers.

Media Management and System Maintenance

  • File Compression: Shrinks file sizes to free up storage room. Compressed files are often called zipped files. Types include:

    • Lossy compression

    • Lossless compression

  • Media Player: Allows viewing of images, animation, audio, and video.

  • Disc Burning Software: Writes files to recordable or rewritable optical discs.

  • Personal Computer Maintenance Utility: Identifies/fixes OS problems, repairs disk issues, and improves performance.