This system was designed to solve problems with the original BIOS or to add new functionality. This allows users to update the BIOS version on computers after a vendor releases an update. We can also use flash-memory cards to hold BIOS information. Features vary among individual BIOS versions. This setup screen often allows users to change the order in which drives are accessed during startup and control the functionality of a number of critical devices.
The setup screen is typically accessed with a special key sequence during the first moments of startup. Computer users can often make certain adjustments to the BIOS through a configuration screen on the computer. Once the basic instructions have been loaded and the self-test has been passed, the computer can proceed with loading the operating system from one of the attached drives.
The BIOS also works to give the computer basic information about how to interact with some critical components, such as drives and memory that it will need to load the operating system. Error codes are typically a series of beeps heard shortly after startup. If errors are detected during the test, the BIOS instruct the computer to give a code that reveals the problem. Then additional tests are done during booting. This self test ensures that the computer has all of the necessary parts and functionality needed to successfully start itself, such as use of memory, a keyboard and other parts. (i) BIOS Power on Self Test (POST): It is a built-in diagnostic program.