1. A method for installing a protected software product using an unprotected installation image, comprising: initiating an installation process on a client computer system for installation of a protected software product; in response to initiating the installation process, installing an unprotected software executable file included in a first installation image into the client computer system; deleting the unprotected software executable from the client computer system after installing the unprotected software and before terminating the installation process; and writing a 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.