<P> Later, 386 - class computers started integrating the BIOS setup utility in the ROM itself, alongside the BIOS code; these computers usually boot into the BIOS setup utility if a certain key or key combination is pressed, otherwise the BIOS POST and boot process are executed . </P> <P> A modern BIOS setup utility has a menu - based user interface (UI) accessed by pressing a certain key on the keyboard when the PC starts . Usually the key is advertised for short time during the early startup, for example "Press F1 to enter CMOS setup". The actual key depends on specific hardware . Features present in the BIOS setup utility typically include: </P> <Ul> <Li> Configuring the hardware components, including setting their various operating modes and frequencies (for example, selecting how the storage controllers are visible to the operating system, or overclocking the CPU) </Li> <Li> Setting the system clock </Li> <Li> Enabling or disabling system components </Li> <Li> Selecting which devices are potential boot devices, and in which order booting from them will be attempted </Li> <Li> Setting various passwords, such as a password for securing access to the BIOS user interface functions itself and preventing malicious users from booting the system from unauthorized portable storage devices, a password for booting the system, or a hard disk drive password that limits access to it and stays assigned even if the hard disk drive is moved to another computer </Li> </Ul> <Li> Configuring the hardware components, including setting their various operating modes and frequencies (for example, selecting how the storage controllers are visible to the operating system, or overclocking the CPU) </Li>

A computer’s basic input/output system (bios) is a computer program stored in read-only memory (rom)