By definition, a virus is a computer program that is able to copy itself and infect other computers. The first one, according to Wiki pedia, was seen almost half a century ago. The Creeper virus was detected in ARPANET, a predecessor of the World Wide Web. It was using the modem connection to replicate on other PCs and when it achieved its goal, it displayed the following message:"IM THE CREEPER: CATCH ME IF YOU CAN".

Anti virus software is another kind of computer programs that appeared because of the need to disinfect computers from viruses. "Reaper" was the first of its kind and its aim was the Creeper virus. Some people said that they might have shared the same creator, but this was never proved.

Since the first antivirus program, viruses and methods to fight them evolved rapidly. Most of the times, for more details visit to www.software-designers-pro.com the next step in evolution is done by computer viruses and antivirus creators struggle to fight back and invent new ways to clean those pesky bugs.

The common approach of antivirus software is to scan files, memory or registries from your computer and detect malicious code. This code is compared to their virus dictionaries and if a match is found, the antivirus program attempts to clean the suspicious part, without damaging the original data.

Another method of fighting viruses is to monitor computer activity, also known as heuristic analysis. This includes monitoring memory and ports traffic for any signs of infection.

A modern approach is the so called "sandbox" method. It involves running the suspicious file into a simulated operating system and analyzing the results. No matter the method, if a virus is found, for more details visit to www.viral-toolbar-builder.com the antivirus first attempts to disinfect the file. If it's unsuccessful, the infected file is quarantined (isolated from other programs) or in worst case, deleted.

It's very important to have a reliable antivirus program installed because there can be viruses on a file you download, inside an email attachment or even a website can include some malicious code to infect your PC.

Some of the programs that are out there and can do the task are free, but most of them require payment. Almost all include updates of their virus's database, to make sure your PC is protected to the newest threats.

AVG Anti-Virus Free, Bit Defender Free, Comoro Antivirus and PC Tools Antivirus Free Edition are only a couple of the free antivirus programs available on the Internet.