The majority of personal computers use a built-in software program called the Basic Input/Output System (BIOS) to control interactions among the devices in the machine and allow the user to configure certain personal settings. On a business notebook such as the HP Compaq nc6400, one of the most likely settings that a user is likely to adjust in the BIOS is the password that the computer requires when it is turned on. By setting a power-on password in the BIOS, you can deter potential snoops from accessing sensitive information if they are able to gain physical access to the computer. These and other settings are available in the HP Compaq nc6400 BIOS by pressing a key as the computer starts up.
Click the "Start" button in the bottom-left corner of the screen, then click "Turn Off Computer."
Click the green "Restart" button. The computer begins to reboot.
Tap the "F10" key on the keyboard repeatedly as soon as the HP Compaq nc6400 screen goes dark. After a moment, the BIOS configuration screen appears. Make the desired changes.
Select "Save and Exit" so leave the BIOS set-up and save the new configuration after making the desired changes.
There is a small window in which you can press the "F10" key to enter the HP Compaq nc6400 BIOS set-up. If you miss this window and Windows begins loading, do not shut the computer off. Allow the operating system to load completely, restart the computer and try again. In 2007, HP released a BIOS update for the HP Compaq nc6400. This update improves the computer's tolerance to environments that are outside of its recommended temperature range and may prove useful for most users.