Computer viruses have come to stay and there’s nothing we can do about that. However it is extremely important to know how they are transmitted if we want to prevent them.
-These days, most of the viruses spread due to receiving spam e-mail messages that contains viruses. When a an unsuspecting user opens such an infected message, the virus is also loaded into the computer memory. Many other program files become infected with the virus and become corrupt and useless. Some viruses even trigger automated messages. Do not open spam mails at all. Open only e-mails from known and trusted senders.
-The internet and local area networks also serve as a breeding ground for viruses. When you download executable files from the internet, shared online disc and other unmonitored file sharing sites, your computer can get infected. In most cases, free PHP or ASP scripts are the main source of virus, always get these scripts from reliable sources. If a computer is infected with a virus in a LAN, all computers on that network may become infected.
-File transfer from and to removable disks such as flash drive, MP3 player, ipod, CD, DVD can also infect your computer with virus.
-Pirated softwares can also infect your PC with spywares and other unwanted programs. Some programmers often incorporate such malicious codes into their softwares. Keygens(key generators) are also reported to have caused damages to computers.