Abstract: The present invention provides a method and apparatus for automatically installing an operating system on a computer via a serial port of the computer. An installer machine running an installation program connects to the computer to be installed via a serial port of the computer to form an ASCII connection with the computer. Once the connection is made, the installation program sends commands to the boot ROM of the computer to institute the installation process. The computer program then waits for configuration questions to be asked by the boot ROM of the computer and sends the appropriate answers to the questions. Preferably, the installer is connected to the machines to be installed via a multiplexer/demultiplexer device which is connected to the serial ports of the machines to be installed. Thus, the installer is capable of installing operating systems on a plurality of machines by selecting the port number of the multiplexer/demultiplexer device to which the machine to be installed is connected.