in the art may comprise other types of removable storage media or may be downloaded onto the hard drive of data loader 160 the authorization medium 200 comprises an authorization list 210 that in one embodiment is encrypted in a manner that only software provided by the vendor of a set of installation disks may decrypt those of skill in the art appreciate that the encryption algorithms referred to in regards to this specification may be implemented through any one of a number of commonly used algorithms such as des pgp rsa rabin elliptic curve encryption el gamal or bitwise xor techniques the authorization list 210 is stored on the authorization medium 200 and is comprised of either a list of alphanumeric serial numbers 220 a countdown datum 230 or both in one embodiment countdown datum 230 is an integer value that is pre set by the software vendor in another embodiment serial numbers 220 are also pre set by the software vendor in yet another embodiment serial numbers 220 may be supplied in whole or part by the software customer in a manner as described below that limits the number of authorized serial numbers that can be added to the authorization list fig3 illustrates in flow chart form one of the embodiments of the present invention to.