Operating system - U1

• Operating System (OS)

  System software that controls the hardware and allows communication between the user and the computer system
• Examples of Operating Systems

  • Microsoft Windows
  • Mac OS
  • Linux
  • Android
• Functions of Operating Systems

  • Provides a user interface (GUI)
  • Memory management
  • Processor management
  • File management
  • Hardware management
  • System security management
  • Error handling
• GUI (Graphical User Interface)


  Makes use of windows, icons, menus, and pointers
• Memory management


  1. Deals with the loading and running of applications

  2. Allocates memory space to programs and data

  3. Keeps track of which parts of memory is in use and which parts are free
• Processor management


  1. Allocates processor time (CPU time) to different tasks being performed simultaneously

  2. Gives a time slice to each job that needs to be processed
• File management


  1. Manages the transfer of data and files

  2. Helps save work, organise files, find files, and load files
• Hardware management (peripheral management)

  1. Controls all input devices attached to the computer

  2. Accepts and transfers data from input devices to the computer memory

  3. Ensures output is sent to the correct output device

  4. Manages the transfer of data between memory and storage devices
• System security management


  1. Monitors and restricts access to programs and data

  2. Prevents unauthorized access by checking username and passwords
• Error handling


  Deals with errors that occur when a program is being run or when data is being transferred, and informs the user
• Single-user system


  An operating system that can be used by only one person at a time
• Multi-user system


  An operating system that allows multiple users to access a computer's resources at a time
• Multi-processing system


  An operating system capable of supporting and utilising more than one computer processor
• Multi-tasking system


  An operating system capable of allowing several programs to run at the same time
• Troubleshooting


  The process of identifying and resolving a problem in a computer system
• Troubleshooting: The computer does not start


  1. Check that the power cord is plugged securely

  2. Make sure the power socket/outlet is working

  3. If using a laptop, check if the battery is charged
• Troubleshooting: The computer freezes (becomes unresponsive)

  1. Push Ctrl, Alt, and Delete keys

  2. In Task Manager, select a task and click End Task

  3. Perform a hard reboot by pressing and holding the power button for 10 seconds
• Troubleshooting: The printer is not working


  1. Check if the printer is on

  2. Check if all cables are properly plugged

  3. Check for paper jams

  4. Check if there is ink in the printer
• Troubleshooting: The mouse or keyboard has stopped working


  1. If wired, check if it is properly plugged in

  2. If wireless, check if the batteries are okay
• Troubleshooting: There is no sound


  1. Check if the speakers are on and the volume level is okay

  2. Check that the speakers are well connected to the computer system
• Troubleshooting: The screen is blank


  1. The computer may be in sleep mode, click the mouse or press any button on the keyboard

  2. Make sure the computer is plugged in and switched on

  3. Make sure the monitor is properly plugged in
• Troubleshooting: All programs on your computer run slowly

  1. Run a virus scanner

  2. Delete files you do not need, as the computer might be running out of hard disk space

  3. Run the disk defragmenter
• Troubleshooting: Accidental deletion of a file


  1. Open the Recycle Bin, right-click on the file and click Restore

  2. Press Ctrl + Z on the keyboard to retrieve the file back

  3. Right-click where the file was located and select "Undo Delete"
• Peripheral

  All input devices, output devices and storage devices connected to and controlled by the computer system
• Server

  It is a computer that provides data to other computers
• Terminal

  It is a personal computer connected to a network.