1. A method for installing a protected software product using an unprotected installation image, comprising: loading a master installation image encoded on and loaded locally from a computer-readable medium to initiate an installation process on a client computer system to effect installation of the protected software product, the master installation image including (i) a master installation executable, (ii) the unprotected installation image comprising a damaged unprotected version of a software executable that is deliberately and irreversibly corrupted so that it will not run and cannot be decompiled, and (iii) a protected version of the software executable; in response to initiating the installation process, installing the damaged unprotected software executable into the client computer system; deleting the damaged unprotected software executable from the client computer system after installing the unprotected software and before terminating the installation process; and writing the protected version of the software executable to a memory of the client computer in place of the unprotected software executable that is deleted from the client computer system, to complete installation of the protected software product.