The computer virus is something that has been around almost as long as the Personal Computer (PC) and certainly since the advent of the affordable home computer, but what exactly is a virus? And how does it affect your PC? Is there any way to prevent your hard drive becoming infected and just where do they come from anyway? A virus is computer program, usually a very small program, that interferes with the smooth running of a computer's operating system and hardware. Viruses are designed to copy themselves and hide within your computer to a ....