What is an Operating System (OS)?
An Operating System is a SYSTEM SOFTWARE that CONTROLS THE HARDWARE and ALLOWS COMMUNICATION between the USER and the COMPUTER SYSTEM. It is the MOST IMPORTANT software in a computer system.
Examples of OS
- Microsoft Windows- most common & used OS in PCs.
- MAC OS X- OS used in computers manufactured by Apple Inc.
- Linux- Free OS that can be installed on PCs.
- Android- OS used with Android compatible smart phones & PC tablets.
Functions of OS
- It provides a user interface.
-GUI allows interaction with computer system through icons and menus. - Memory management.
-Deals with the loading and running of application programs.
-Allocates memory space to programs & data.
-Keeps track of which parts of the memory are in use & which parts are free. - Processor management
-Processor time (CPU time) allocation for each task to be processed.
-Time slice given to each job to be processed - File management
-Manages transfer of data & files.
-Helps us to save our work, org. our files & find files that we have saved and load files. - Hardware management (peripheral management)
-Controls all attached devices.
-Accepts & transfers data from input devices to the computer’s memory.
-It makes sure that any output is sent to the correct output device.
-Manages transfer of data between computer’s memory & backing storage devices. - System security management
-Monitors & restricts access to programs and data.
-Prevents unauthorised access to the computer system by checking usernames & passwords. - Error handling.
-Deals with errors that occur when program is being run, or when data is being transfered somewhere & informs the user if necessary.
Types of Operating Systems
- Single-user system:
-An OS that supports ONLY ONE user AT A TIME. - Multi-user system:
-An OS that allows MULTIPLE USERS to access a computer’s resources at the SAME TIME.
-SERVERS AND TERMINALS are used. - Multi-processing system:
-OS capable of supporting & utilising MORE THAN ONE computer processor. - Multi-tasking system:
-OS capable for allowing SEVERAL programs to run at the SAME TIME.
What is a server & terminal?
- A server is a computer that provides data to other computers.
- A terminal is a PC connected to a network.
What is Troubleshooting?
Troubleshooting is the process of IDENTIFYING & RESOLVING a problem in a computer system. It is used to solve problems with HARDWARE & SOFTWARE.
Problem 1: The computer does not start.
Solution 1: Check that the power cord is plugged securely into the back of the system unit and the power outlet.
Solution 2: If power cord is securely plugged in, make sure that power outlet is working. Plug in another electrical device such as a lamp to check whether the power outlet is functioning properly.
Solution 3: If a laptop is being used, the battery may not be charged. Plug in AC adapter, wait for few mins and try to turn on the laptop.
Problem 2: The computer freezes (becomes unresponsive).
NOTE: IF COMPUTER IS UNRESPONSIVE, YOU WILL NOT BE ABLE TO CLICK ANYWHERE ON THE SCREEN, OPEN/CLOSE APPLICATIONS, OR ACCESS SHUT DOWN OPTIONS.
Solution 1: Press [Ctrl+Alt+Delete] keys at the same time to start Task Manager and click the End Task Button.
Solution 2: Perform a hard reboot by simply pressing and holding on/off button for 5 to 10 seconds to turn off the computer manually. This action should be done as last resort as it could cause data loss or corruption.
Solution 3: If the computer will not shut down, unplug the power cable from electrical outlet. If laptop is being used, remove the battery to force the system to turn off.
Problem 3: The printer is not working.
NOTE: A PRINTER REQUIRES INK & PAPER TO PRODUCE PRINTOUTS. THEREFORE, BEFORE PRINTING, CHECK INK/TONER LEVELS & LOAD PAPER IN THE SHEET FEEDER.
Solution 1: Check if printer is turned on. If not, turn on and try again.
Solution 2: Ensure that all cables are properly connected. Try again.
Solution 3: Check if printer has a paper jam. If so, remove jammed paper, close printer & try printing again.
Problem 4: The mouse & keyboard has stopped working.
Solution 1: If you are using a wired mouse/keyboard, make sure it is correctly plugged into the system unit. If not, plug it in properly.
Solution 2: If you are using a wireless mouse/keyboard, try changing batteries.
Problem 5: The sound is not working.
Solution 1: Check volume level. Make sure that the sound is turned on & that the volume is up.
Solution 2: Check the cables. Make sure external speakers are properly plugged in, turned on and connected to the correct audio port or a USB port.
Problem 6: The screen is blank.
Solution 1: The computer may be in ‘Sleep’ mode. Click the mouse or press any key on the keyboard to wake it up.
Solution 2: Make sure that the computer is plugged in & turned on.
Solution 3: If a desktop computer is being used, make sure the monitor cable is properly connected to the system unit and the monitor.
Problem 7: All programs on the computer run slowly.
Solution 1: Run a virus scanner (anti-virus) There may be a malware running in the background that is slowing down the computer system.
Solution 2: Your computer may be running out if hard drive space.
-Try deleting some files or programs that are not being used.
-Run ‘Disk Defragmenter’ which is a utility software designed to increase access speed by rearranging files on a stored disk.
Problem 8: Accidental deletion of a file.
Solution 1: Open Recycle Bin. Right-click on the file & click on restore
Solution 2: Press Ctrl+Z on the keyboard to retrieve the file back.
Solution 3: Right-click where the file was located and select “Undo Delete”.
