Computer viruses are programs written by unscrupolious people. These virus programs are placed into a commonly used program so that program will run the attached virus program as it boots. The virus "infects" the executable file of program.
A ".exe" file is the file that you click on to start a program on your computer.
For example: When you click on your internet explorer icon on your desktop, it runs the " iexplorer.exe " file.
A virus is inactive until you execute an infected program or application OR start your computer from a disk that has infected system files. Once a virus is active, it loads into your computer's memory and may save itself to your hard drive or copies itself to applications or system files on disks you use.
Some viruses are programmed specifically to damage the data on your computer by corrupting programs, deleting files, or even erasing your entire hard drive.
Many viruses do nothing more than display a message or make sounds / verbal comments at a certain time or a programming event after replicating themselves to be picked up by other users one way or another.
Other viruses make your computer's system behave erratically or crash frequently.
Sadly many people who have problems or frequent crashes using their computers do not realize that they have a virus and live with the inconveniences.
