MCI uses the DriverProc entry point to handle its messages for MCI services. MCI augments the messages needed by the system to install, initialize, and configure the driver with MCI specific messages. This chapter contains a description of the messages added by MCI. While this chapter will reference the messages used by the system, it will only reference them in relation to the MCI messages. The Microsoft Windows Software Development Kit provides the complete definition and use of the messages used by the system.