A method and apparatus for protecting computer systems from a virus are disclosed. For example, the present method protects against a class of computer viruses that replicate themselves by making use of the knowledge that a specific piece of software code or data component that always resides at a specific relative memory location in RAM for all instances of the software. In one embodiment, the present method divides a software application into a plurality of components and creates distinct copies of the software application by varying the locations of the components when loaded onto a computer system.