Abstract: The present invention relates to a computer firewall system, comprising an electronic erasable memory, a magnetic sector comparator, an interrupt output, and a firewall firmware, and being placed into a hard disk controller or in the internal circuit of the hard disk drive; the hard disk drive is divided into a plurality of partition areas, and the system monitors the data access of the partition areas by the program in order to prevent the operating system from being damaged and to protect the desired data or specific partition areas, thereby the users can feel ease to use the computer because the present invention has the function of minimizing the fear feeling of computer virus, computer hacker, unintentional delete, bad-intention delete, or data damage.