1. Slow Performance: If your computer suddenly becomes significantly slower than usual, taking longer to boot up, open applications, or respond to commands, it could be a sign of a virus. Viruses can consume system resources, resulting in decreased performance.

2. Frequent Crashes: If your computer frequently crashes, freezes, or experiences sudden system reboots without any apparent reason, it could be due to a virus. Some viruses can interfere with system stability, leading to unexpected crashes or instability.

3. Unusual Pop-ups or Ads: If you start noticing an excessive number of pop-ups, advertisements, or banners appearing on your computer screen, especially when you're not browsing the internet, it might be an indication of adware or malware infection.

4. Unwanted Modifications: Viruses can modify system settings or configurations without your consent. If you observe changes in your default browser homepage, new toolbars appearing, unfamiliar icons on the desktop, or altered settings, it could be a sign of a virus.

5. Unusual Network Activity: If you notice excessive network traffic, unusual data transfers, or a sudden increase in data usage without any known reason, it could be an indication of a virus or malware actively communicating with external servers.

6. Missing or Modified Files: Viruses can delete, encrypt, or modify files on your computer. If you find missing files or encounter unexpected changes in file sizes, names, or extensions, it could be a result of a virus infection.

7. Disabled Security Software: Some viruses attempt to disable or circumvent antivirus or security software to avoid detection. If you notice that your antivirus program or firewall is deactivated, modified, or unable to update, it could be due to a virus compromising your security software.

8. Unexpected Email or Message Activity: Viruses can use infected computers to send spam emails or messages to contacts in your address book without your knowledge. If your friends or colleagues report receiving suspicious or unexpected emails or messages from you, it could be a sign of a virus.

• It requires that a foreign key must have a matching primary key or it must be null

• Labels
• Values
• Formula
• Functions

A computer virus is a program designed to damage other programs or causes irregular behaviour in a computer system.

• Installing the latest versions of antivirus software
• Avoiding downloads from untrusted sites
• Scanning removable storage media for viruses before use
• Scanning attachments for viruses before opening or downloading

(a) \(F C_{16}\)

(b) \(8 A_{16}\)

(c) \(93_{10}\)

 Control unit

(a)State what is meant by the terms:

Parallel data transmission

• 8 bits/1 byte/multiple bits sent at a time  
• using many/multiple/8 wires/lines

Serial data transmission

• one bit sent at a time over a single wire

• It is the use of proofing tools like spelling and grammar checkers and autocorrects to check whether a document has typographical or grammatical errors

• once instructions are given, the processing runs automatically hence requiring little supervision
• tasks are processed as a group hence reducing the cost
• It is faster since the since runs automatically
• there is increased output since the processor works without any interruption

• System software that analyses, configures, optimises and maintains a computer system

1. a) Based on Deutro-Isaiah, describe the Messiah. (7mks)

The Messiah would be despised/ rejected

The Messiah would be treated harshly/ arrested/sentenced to death

The Messiah would be reconciling people through His suffering

The death of the Messiah would bring forgiveness of sins of humankind

The Messiah would endure suffering/humiliation without complaining/ would suffer innocently

The Messiah would have nothing attractive

The Messiah would be humble/simple

The Messiah would be highly honored

The Messiah would succeed in His work

He would be despised, rejected, wounded oppressed and afflicted 

He endured pain and suffering which would have been ours. 

Because of our sins he was wounded 

We are healed by the punishment he suffered He was treated harshly but he never said a word 

He was put in the grave with the wicked 

He was buried with the rich even though he did not commit a crime 

He took the place of many sinners and prayed that they might be forgiven.

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

Phased:
Advantages:

• only a small part of the operation affected if new system fails
•  no need to pay for two sets of wages

Disadvantages:

•  time consuming (each part needs testing fully before expanding system)

Pilot:
Advantages:

• if new system fails, only that part will be affected
• possible to gradually train staff on pilot before whole system changes over

Disadvantages:

•  time consuming (waiting to see how pilot works before rolling out to rest of the organisation)

Direct:
Advantages:

•  less likely to malfunction since fully tested
• immediate benefits/less time wasted
•  reduced costs (only one system so no need to duplicate staff)

Disadvantages:

• disastrous if the new systems does fail

Parallel:
Advantages:

•  if new system goes down, there is a backup system in place
• possible to gradually train staff/staff have time to get used to the new system

• Recommendation on whether to continue or abandon the project
• Methods used to collect data
• benefits and limitations expected
• the technology required to develop and maintain the project
• Installation and running cost
• Time limit

System analyst

Web designers

Network administrators

Database administrators

Programmers

Computer technicians

• 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

• Radiowaves are omnidirectional while microwaves propagate in one direction at a time(unidirectional)
• Radiowaves can be propagated over long distances through sky mode while microwaves require a relay satellite to amplify and retransmit the microwaves signals to the receiver earth station

a)Spreadsheets                                                                                                                               (2mks)

• Microsoft Excel
• Lotus 1-2-3
• Google Sheets
• OpenOffice Calc

                                           Any 2 @ 1mk

b) Word processors                                                                                                                          (2mks)

• Microsoft Word
• Wordpad
• Corel WordPerfect
• Lotus Word Pro

                                         Any 2 @ 1mk

Advantages

• Sharing of software and data files
• Sharing of hardware, e.g. printers
• Communication

Disadvantages

• Security of files is more of a problem