A virus can cause harm to a computer, its programs and files stored in it. Lost data can usually be recovered by data recovery programs. A virus may be simple enough to cause the computer to halt, or it may be as complicated as a spyware that sends information back to the creator. Most computer viruses can attach themselves to all types of files used. They commonly attack the boot information of the computer and the hard disk boot sector. The virus is thus able replicate itself when you reboot your computer.

There are three ways in which a computer virus is spread; using removable media, use of downloaded files, and using email attachments. Viruses do not spread by the plain text files of emails, but through files attached to the mails. However, only after the attachment is opened by the user, can the virus become active. Worms and Trojans are also threats, which do not replicate themselves like viruses. They wait for some trigger, and then they proceed to steal information to send back to their creator.

Computer viruses were first seen in the 1980s. They appeared in the mainframes such as UNIVAC 1108 and IBM 370. The viruses made life miserable for the early users by disabling system files, hard drives, and speakers. Anti-virus software started to appear for tackling the Brain virus which attacked the boot sector of PCs. This was probably the first virus to attack PCs. Initially, the anti-virus programs were virus specific, but soon their growing number caused companies to develop full-fledged software packages to remove viruses from computers.

Viruses can cause a complete failure of a computer or server. They can cause identity theft and information loss. They may cause a user’s browser to get redirected. They may also be used to place certain ads and unwanted links on the user’s web-page. Viruses can also affect the boot sector and render the computer useless. But the most damage they can do is when they enter the registry files. The passwords and configuration files contained therein may get stolen. Most anti-virus programs use a list of known viruses and their patterns to detect them. Special anti-virus programs are needed to cleanup computer with specific malware and spyware.

Threats from viruses are constantly changing and regular checks should be done to locate them. The anti-virus programs should be updated frequently, and other notifications about viruses should also be tracked. Information is the most sought after today, and most viruses and trojans are designed to retrieve information. Prevention usually takes the form of periodic backup of files and data, running regular scans, and removing the viruses located in the scans. The anti-virus programs used, should also be used to scan the email attachments prior to download. Recovery is then simply a matter of restoring the backed up files after cleaning up your computer. It is recommended to note the identity of the virus and check the anti-virus program has the capability to deal with it in the future.

Nowadays, our computers are connected to the internet most of the time. From the time, you log on into the internet, you are connected to an external computer called the server. The server is only a channel to connect to the internet, and you get the facility to connect to any other computer on the net, and in the reverse way any other computer wishing to connect to you, can do so. This is also the way; you are exposing your computer to the threats from the external world, in addition to the benefits of enjoying the improved communication.

To remove viruses from computer, you may already have an anti-virus program installed and running on your computer. This is adequate when you are off-line, that is disconnected from the net. However, the menaces of the internet are a bit tougher than your anti-virus program can handle. Consequently, you will need something more, apart from your anti-virus alone. The configuration of your anti-virus program is also important. The program you select should have auto scanning feature, the frequency of which you can adjust to suiting your way of working. If you work with a lot of files which you receive from outside sources, you should set to a more frequent scanning. Purchase a legitimate package of the anti-virus program, since illegal ones may themselves be carrying a computer virus.

Your browser will have parental control. You will be able to blacklist specific URL’s so that users of the browser will not be able to access them. In case you have multiple machines, all can have independent parental control. Most websites will give their rating, with which you can restrict the type of websites that can be accessed. Many adult sites contain malicious software, virus, Trojans, and spyware. By restricting access to these websites, not only are you saving your kids from such adverse content, you are also saving your computer from falling prey to the external attacks.

It is always wise to disconnect from the internet when you are done. This way, you reduce the exposure. Also, allow the anti-virus program to update its security features as often as possible. New viruses are all the time getting added to the net and the anti-virus people have a tough time locating them and finding ways and means to block them. Therefore, there is no set time or schedule when they will be sending the updates for security. It is a good idea to follow a religiously strict regimen to periodically scan your computer and weed out any accumulated threats and affected files.

Responsible use of the internet goes a long way in defining computer security from the internet marauders. Make sure you run software, which is legitimate and purchased from trusted sources. Files coming from external sources should be presented to the anti-virus checking before use. Electronic mail attachments should be scanned before downloading. Be a responsible user and scan your computer and outgoing files to make sure you are not the inadvertent source of the threat.