A system and method of selectively installing software onto a computer system which includes reading a configuration file that contains computer system information, determining an encryption key from data contained in the configuration file, and deciphering data stored on a nonvolatile storage device using the encryption key. The computer system information includes system specific information that may be used to determine whether the computer system was purchased from a particular vendor. In a Windows.TM. based application, the configuration file includes a BIOS/DOS file that includes computer system specific information and the encryption key is optionally stored in a registry file to provide for repeated uses of the encryption key if more than one data file are being deciphered. In another embodiment, the data file is stored on a World Wide Web page accessible over a global computer network, such as the Internet, to install and decipher encrypted data files stored on a Web server.