What Viruses Are A program that performs actions with or on your computer that is generally not intended, and usually is destructive in nature.
Most viruses operate after being activated without further interaction performed by the user.
Initially transferred from computer to computer on disks swapped between machine, but now are commonly sent as attachments or embedded in e-mails and web pages. Some viruses will delete specific types of files on your system, targeting image or music files, or word processing documents or spreadsheets. Others will change settings in your e-mail programs or web browser. There are numerous companies that make software that you can install on your computer to help protect you from viruses and trojan programs. A few are listed above.