SYSTEM AND METHOD OF PROTECTING INTEGRITY OF COMPUTER DATA AND SOFTWARE

System and method for preventing alteration of stored data by computer virus. In a computer system which normally automatically boots an operating system when the central processing unit is initialized, a device is provided which takes control of the central processing unit before boot-up, checks the system files for computer virus and generates an alarm signal if a virus is detected. In the preferred embodiment, the device quarantines an infected operating system to prevent alteration.