Antivirus Programs - The term, computer virus describes a potentially demaging computer program that affect, or infects, a computer negatively by altering the way the computer work without the user's knowledge or permision. Once the virus is a computer, it can spread throughtout and may demage your files and opearting system.

Computer viruses do not generate by chance. The programer of a virus, known as a virus author, intentionally writes viruses a challenge. Others write virus programs to cause destruction. Writing a virus program usually requires significant programing skills.

Some viruses are harmless pranks that simply freeze a computer temporarily or display sound or massages. The music bug virus, for example : instructs the computer to play a few chords of music. Other viruses destroy or corrupt data shared on the hard disk of the infected computer. If you notice any usual changes in your computer's performance, it may be infected with a virus.

Viruses are just one type of malicious software. Malware (short for malicious software) is software that acts without a user's knowledge and deliberately aalters the computer's operations. In addition to viruses, worm and trojan horses are melware.

A worm, such as sasser or klez, copies itself repeatedly for example : in memory over a network using up system resource and posibly shutting down the system. A trojan horse (named after the hreek myth) hides within or looks like a legitimate program such as a screen server. A certain condition or action usually trigers the trojan horse. Unlike a virus or worm, a trojan horse does not replicate itself to other computers. Currently more than one milion known threats to your computer exist.

To protect a computer from virus attacks, users should install an antivirus program and update it frequently. An antivirus program protect a computer against by identifying and removing any computer viruses found in memory, on stroge media, or on incoming files. Most antivirus programs also protect againts worms and trojan. When you purchase a new computer, it often includes antivirus software.

There more popular antivirus programs are Mcafee virus scan, Eset NOD 32, Norton anti virus, Avira,  Avast, Panda, Bitdefender, symantec, f-secure,  trend micro, most of which also contains spyware removers, internet filters and other utilities. As an alternative to purchasing these products on disc, both McAfee and Norton offer web based antivirus programs.