Final answer:
Access to the BIOS system setup is gained by pressing a specific key during the computer's boot-up process, usually one of the function keys or 'DEL'.
Step-by-step explanation:
To attain access to the basic input/output services (BIOS) system setup, you typically need to restart your computer and press a specific key during the boot-up process. Depending on the computer's manufacturer, the key to press can be F1, F2, DEL, ESC, or another function key. As soon as you turn on the computer, you should pay attention to the screen, since it often displays a message such as 'Press [Key] to enter Setup' or 'Press [Key] to enter BIOS.'
Once you press the correct key, you will enter the BIOS setup utility. This is a pre-operating system environment where you can configure hardware settings, including boot sequence, system time and date, as well as hardware components. To navigate the BIOS, use the keyboard arrows and follow the on-screen instructions to make changes, ensuring you save the settings before exiting.