This document provides an overview of computer viruses. It discusses how viruses spread by attaching themselves to files and transferring between computers. Various types of viruses are described like boot viruses, polymorphic viruses, macro viruses, worms, and trojans. Symptoms of a virus infection include slow performance, reduced memory, and files becoming corrupted. The document recommends installing antivirus software, regularly updating it, and being cautious of email attachments to prevent and cure virus infections.

1. A Presentation On Computer Viruses
Name:- Nitish Xavier Tirkey
F.Y.BCA
Date:- 4th October, 2010

2. Flow of presentation
• Introduction
• Symptoms
• How does it spread
• Types of Computer Viruses
• Prevention and Cure
• Antivirus Software
• Conclusion

3. Introduction
• Computer viruses are a type of software program that,
like a biological virus, reproduces and spreads itself
• Some virus may display only a message on the screen,
others may slow down the Pc
• They can also erase files or even format your floppy or
hard disk and crash the system

4. Symptoms
• Letters looks like they are falling to the bottom of the
screen.
• The computer system becomes slow.
• The size of available free memory reduces.
• The hard disk runs out of space.
• The computer does not boot.

5. How does it spread
• Computer viruses spread by attaching themselves to
other computer program files
• When you exchange a file or pen drive with a virus, the
virus spreads from one computer to the another
• Viruses also spreads when a Computer Engineer comes
to repair your system and puts his/her diagnostics disks
in your PC

6. Types of computer viruses
• Boot viruses:- The boot virus copies the virus code in
the boot sector
• Polymorphic viruses:- They are coded in such a way
that they infect a system and change their signature
• Macro viruses:- Macros are blocks of code written to
automate frequently performed tasks and embedded in a
program file
• Worms:- Worms are program that replicate and spread
to other system
• Trojans:- A Trojan is a program file that claims to do
something but it actually does something that is not
required

7. Preservation and cure
• Install an Antivirus software
• Regularly update the program
• Open email attachment files only if you are expecting the
attached files, or the sender is known and has confirmed
sending the file
• Try to avoid downloading and installing software from
the Internet
• Install only registered copies of software on the system

8. Antivirus Software
• Norton Anti-Virus
• MaCfee
• Avast
• Quick Heal
• Panda

9. Conclusion
• For better and safe computation anti-virus software
should be installed and be helpfull for global network
system freely.

10. Thank You