A method and apparatus for controlling the movement of owned computer parts to prevent theft of the computer parts for use in a different computer system. A code is defined to identify an owner of a system or group of systems, and this code is programmed into non-volatile memory located on the systems and parts belonging to that owner. The system software automatically does a comparison of all parts in the system to ensure that the code on each part is compatible with that on the system. A given computer part will not function if it is installed into a system which does not have a code compatible with that of the part. This invention makes stolen parts useless, and knowledge of the existence of this invention is a theft deterrent. The owner can choose to change this code periodically by entering the value of the previous code. Also, the owner can activate or deactivate the security for a particular part by resetting a bit in the code field of that particular part, which can only be done if the part security code is compatible with the system security code. If this enabling bit is not set, the comparison will not be done and the part will work on any system.