If a virus once enters in computer it can create major problem. Its effects depend greatly on the whole data entered by operator. Once on your computer, a virus might corrupt or worse, delete your data. Some viruses are leaves less effects on computer some viruses corrupt whole data both are dangerous, as they can corrupt and damage your files.
One thing a virus is not capable of doing is damaging any of your computer’s physical hardware.
Do you know a small virus on computer can be corrupt whole data? And when the worm infects a computer it searches the email address book and tries to send itself to all the addresses it finds.
These viruses help to the cyber criminals which are increasingly focusing their attacks on the hundreds of millions of users of social networks and on loopholes in bank security systems, security software vendors.
When some people try to get rid of viruses they delete files or they might even format the whole hard disk like my cousin did. That is not the best way to act when the person think that he has a virus infection.