Abstract: Anti virus device is an electric mechanical circuitry to protect the hard disks of computers from virus, hooked up to the hard disk, with electric mechanical selection for the hard disk protected area, externally performed by the user, with totally isolated operation from the programs processed by the computer, with independent functionality from the virus nature or newness and immune itself from the virus attack, based on the functionality allowed by the creation of reserved areas at the hard disk, with local and size strictly determined; the first step being the demarcation of the hard disk areas where each area will be protected by a electrical breaker (part of the device) connected to the control unit through a logical port (AND, NAND or any other) and this logic enabling or disabling writing at the magnetic media of the hard disk according to the user needs, by the electrical breaker position.