Most common viruses and their cure

Hi,
I normally don't much about the viruses. But I want to know that what are the most common viruses which affects the computer. What are their effects and what type of anitivirus is best available on the internet to kill them. What are the most common attacks or threats to the computer. If a system got affected then what are the harm done by these attacks.

Whoever is connected with internet is prone to some of the viruses and threat's.
The known threats are :
a). Denial of Service (DOS/DDOS) :
Makes your Network slow, increase number of spams, unable to access website.
b).Back Door
It is created while not properly removing some software called malicious software.
c).Spoofing
Increases in number of unwanted mails.
d).Man in the Middle
Under this attack the users gets mail from any known user. But on the other side the user had not send any mail.
Other than this there are many other threats.
You can use a good antivirus to avoid such attach. You need to scan your system regularly.
Some Antivirus :
Nortorn Internet Security
AVG Internet Security

The most common type of virus which are a threat to system are :

Macro virus -
It normally comes in documents or spreadsheets or mails.
ILOVEYOU and Mellissa are common examples.

Boot sector virus -
It overwrites the boot sector of a hard drive. This makes your pc dead.
F-Prot, NYB, AntiExe

File infector virus -
It is attached in executables like .exe files or setup files.this type of virus attaches itself to executables, for example .com and .exe files.
Jerusalem and Cascade viruses are common examples.

As you can aware yourself about this threats and use a proper Antivirus tools for the same.

Your system can get infected through various ways. If you are on the internet without your Firewall on, or Infected USB, Malicious Softwares, Networking,etc
The important thing is that to practice safe computing before your system crash down.
Viruses not only affects the system but also the valuable data of a user.
It very important that you must have a very power antivirus utility program
to control and avoid viruses.
Except mails and download files from trusted sources only.
Regular updates.
I listing some of the most powerful antivirus utility you can use:
Avira
Mcafee
Kapersky
BitDefender
F-Prot Antivirus

I also found K7 Antivirus Software to be very good at removing viruses. They are also based in India.