There could be several possible causes for the issues Jane is experiencing with her computer keyboard, including:

1. Software Issues
   - Cause: Outdated or corrupt system files, drivers, or operating system.
   - Solution:
     - Ensure the operating system and drivers are up-to-date.
     - Run a system file checker to repair any corrupted system files (e.g., on Windows, run "sfc /scannow" from the Command Prompt).
     - Consider reinstalling the operating system if issues persist.

2. Hardware Issues:
   - Cause: Physical damage or malfunction in the keyboard hardware.
   - Solution:
     - Check for physical damage or debris under the keys and clean the keyboard if necessary.
     - If cleaning doesn't help, consider replacing the keyboard with a new one.

3. Resource Overload:
   - Cause: The computer may be running too many background processes or lacking sufficient hardware resources.
   - Solution:
     - Close unnecessary background applications and processes to free up system resources.
     - Consider upgrading the computer's RAM, CPU, or storage if it's outdated and unable to handle current software demands.
     - Use task manager or activity monitor to identify and terminate resource-intensive processes.

4. Malware or Viruses:
   - Cause: Malicious software can slow down a computer, cause hanging, and delay startup.
   - Solution:
     - Perform a full system scan using reputable antivirus or anti-malware software to remove any threats.
     - Ensure that the operating system's security patches are up-to-date.

5. Disk Fragmentation:
   - Cause: Fragmented files can slow down the loading of applications and overall system performance.
   - Solution:
     - Run a disk defragmentation tool (e.g., Windows' built-in tool) to optimize file storage on the hard drive.
     - Consider upgrading to a solid-state drive (SSD) for faster application loading times.

6. Insufficient Storage:
   - Cause: If the hard drive is nearly full, it can cause slow performance.
   - Solution:
     - Free up space by deleting unnecessary files and programs.
     - Consider upgrading to a larger capacity hard drive or SSD if storage space remains an issue.

7. Background Processes and Startup Items:
   - Cause: Too many unnecessary programs running in the background or starting up with the computer.
   - Solution:
     - Disable or remove unnecessary startup items and background processes to improve startup time.
     - Use the Task Manager or System Preferences (on macOS) to manage startup items.

It's important to diagnose the specific cause of the issues Jane is facing by troubleshooting each potential problem one by one. In some cases, a combination of these solutions may be necessary to fully resolve the problems with her computer keyboard.

• user changes his mind
• new government legalisation/company policy company changes
• changes in hardware
• changes in software/upgrades/new versions
• improved operating efficiency/ease of use

(a) byte

• fixed number of bits, 8 bits
• represents a character

(b) compiler  program

• converts/changes/translates high-level language into machine code/machine language/low-level language/object code
• changes each high-level language instruction into machine code instructions
• produces an independent program capable of being executed by itself
• all (syntax errors) listed
• converts the whole program before execution/in one go
• converts source code to object code

(c) handshaking

• exchanging of signals to establish communication between two devices/computers e.g. printer and computer, modem and computer

(d) technical documentation

• documentation to ensure that the system can be maintained/updated/altered/developed/upgraded
• trouble shooting/correcting errors/correcting faults
• explanation of what the program does/how the system works
• contains file structures
• algorithms/flow charts/pseudo code
• program listings
• hierarchical chart

(e) simulation

• studying the behavior of a system by using a model/represents real-life/mathematical representation
  e.g. flight simulator (or others), hazardous applications results can be predicted

Modulation refers to the process of converting a digital signal to analog signal at the transmission end while demodulation is to converting analog signal to digital signal at the receiving end

(i) Crop - used when handling a graphic and there is a need to remove some of the portions in the graphic

(ii)Transparency - used when there is a need to make background of a graphic visible

• it is a format style that shows the listed items of different levels rather than at one level. Each level has a different indentation and numbering style

1. Chapter 1

     1.1. Introduction

                 1.1.1.Definition of terms

- Passwords
- Hierarchy
- Only allow some staff to access student files
- Only some machines able to access
- Physical location of these machines
- Physical lock on machines
- Encrypted data in files
- Firewall if connected to the Internet

Define the term internet      1mk

• The global interconnection of computer networks for purpose of communication and resource sharing

Explain the term web page    1mk

• A hypertext  page prepared to display the content on the web

Explain the following internet address http://www.google.co.us in reference to the structure of a URL    3mks

• HTTP- hypertext transfer protocol or simply protocol
• WWW – subdomain
• google – the name of the computer with the web content/domain name
• .co – top level domain for commercial organization
• .us- a TLD extension for the country US

What is the world wide web                                       1mk

•  A virtual space on the internet that allows web pages and sites to be accessed

Define the term browser                                    1mk

•  A software that used viewing of web content

Explain the meaning of the word hyperlink     1mk

• A text or picture that is a link to another webpage on the internet

What is a search engine?     1mk

• Is a special program that collects and stores links to information websites allowing users to search its database for them
• A specialized web-based application that help the user to search for specific information on the internet.

Explain the meaning of the term internet service provider            1mk

• A company that offers internet services to end-users

Identify three elements apart from a computer that is required for one to be connected to the internet    3mk

• Modem
• Internet software
• Internet service provider
• Telecommunication lines
• TCP/IP protocols

Define the term modem 1mk

• Stands for modulator-demodulator
• A device that enables telecommunication to use telephone lines

What is a protocol? Write the following in full: TCP/IP, HTML, HTTP and FTP           5mks

• Protocols – are special communication rules that govern sending and receiving of messages by computers on a network
• Html – hypertext markup language
• Hypertext transfer protocol
• Transmission Control Protocol
• Internet Protocol
• File Transfer Protocol

What would you do if a website refused to load on the browser within the first attempt?   1mk

• Click the refresh button on the toolbar

 State three internet services                         3mks

• Instant messaging
• E-mails
• E-commerce
• Social media and networks
• E-learning

Define the term internet telephony      1mk

• Transmission of voice data over the internet

State three benefits of the internet in our society

• Provides a platform for conducting business and marketing
• Provides many platforms such as social media through which people can contact each other
• Cost saving
• Efficient communication

State the functions of the following protocols

POP -Stands for post office protocol

• used to download emails from email servers

SMTP- Simple Mail Transfer Protocol

• used to send emails to email servers and transfer emails between servers

FTP - Stands for the file transfer protoc

• RSI in wrists or fingers from prolonged typing or repeated clicking of mouse button
• headaches/eyestrain/dry eye from staring at a monitor for long periods of time/glare from monitor
• back ache/strain from sitting in the  same position for a long time/using chair with no adjustment

• A physical file contains the original data whereas a logical file does not contain any data
• A physical file contains one record format while a logical file can contain up to 32 record formats
• A physical file can exist without a logical file while a logical file cannot exist without a physical file

• camera film speed, position (end of film), distance, light
• washing machine amount of water, speed of wash/temperature/time
• fridge temperature, display panel
• air conditioning temperature, timing, display pane

The user is not allowed to access the source code so, they cannot tailor the software to their needs and  they cannot fix any bugs in it

The software is still covered by copyright

The user must get the owner’s permission to do anything beyond using it

• it has a header that contains the destination address, the packet number, and the originator’s address
• it has a payload
• it has a trailer.

• mirrored hard disk/hot standby/second computer
• re-run the old master file with the transaction file

Advantages

• can cover large areas
• requires minimal land-based transmission support
• requires minimal infrastructure to provide internet access
• minimal impact on the environment or humans.

Disadvantages

• transmission speeds are not comparable with other forms of transmission
• data costs are expensive by comparison to other forms of transmission
• expensive to deliver.

(a) Like "*kenya*"

• Returns the records of all countries that contain the string "kenya"

(b) Like "*ina"

• Returns records for all countries/regions whose names end in "ina", such as China and Argentina.

(c) Like U*

• Returns records for all countries/regions whose names start with "U", such as UK, USA, and so on.

(d) Not Like U*

• Returns records for all countries/regions whose names start with a character other than "U".

(e) >= "Mexico"

• Returns records of all countries/regions, beginning with Mexico and continuing through the end of the alphabet.

(f) Like "[A-D]*"

• Returns records for countries/regions whose names start with the letters "A" through "D".

(g) "USA" Or "UK"

• Returns records for USA and UK.

https://support.microsoft.com/en-us/office/examples-of-query-criteria-3197228c-8684-4552-ac03-aba746fb29d8

• Passive matrix create images by scanning the entire screen whereas active matrix displays are made using thin-film transistors technology(TFT)
• active matrix  display has a higher resolution compared to passive matrix
• Active matrix consume more energy than passive matrix

• A compiled program will only execute on a processor of specific type/family/with same instruction set
• A program run using an interpreter can execute on a computer with any type of processor;

Trojan (horse); a program which misleads the user into thinking it is another
piece of software which, when run, executes another program;
Spyware; a program which records data such as usernames and passwords on
a host system and forwards the information to a third party;
Adware; code embedded or attached to program files which will persistently
show adverts (that attempt to generate revenue);
Worm; code which will run autonomously and replicates itself on a host system;
Ransomware; a program that encrypts a user’s data to make it unreadable until
they pay for the key;
Remote Access Tool (RAT); allows access to control and monitor a computer
from a remote network location;
Rootkit; malware that has managed to gain ‘root’ admin privileges;
Bots/Zombies; a program installed on a computer that performs a job for the
remote owner of the bot/zombie such as sending spam or sending web requests
to perform a DOS or attack a computer system;
Scareware; malware that tells you something is wrong with your system in an
attempt to get you to make a purchase;
Keylogger; a program that monitors/records a user’s keystrokes in order to steal
passwords/confidential details