The Platform Configuration Utility (PCU) refers to the configuration utility provided by a hardware or system manufacturer. Examples of PCUs include the ECU (EISA Configuration Utility) for EISA bus systems and the MCU (MCA Configuration Utility) for MCA bus systems. Often these PCUs are originally produced by industry groups and are customized by motherboard manufacturers, and possibly customized still further by system manufacturers). It is run before operating system installation. Much of the autoconfiguration facility is handled by the PCUs. The autoconfiguration facility depends on the PCU having updated the on-board NVRAMs to reflect the hardware configuration for autoconfigurable boards and, in some cases, to include information about ISA cards.