Computer viruses infect a computer in three basic ways: when a user (1) opens an infected file, (2) runs an infected program, or (3) powers on the computer with an infected disk in a disk drive. Today, the most common way a computer becomes infected with a virus is when a user opens an infected e-mail attachment.c
Methods that guarantee a computer or network is totally safe from computer viruses simply do not exist. Users can take several precautions, however, to protect their home and work computers from viruses. …