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monimo | CompTIA A+ | Module 1.1 - Configure and apply BIOS Settings

By: monimo | Related Course: CompTIA A+ | Published: June 14, 2016 | Modified: June 14, 2016
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NotepadBIOS - Basic Input Output System

BIOS = Basic Input Output System

  • Allows to turn on the computer, select an operating system and load some basic information
  • BIOS is a small chip on the motherboard
  • Firmware loaded on BIOS
    • Firmware controls a single hardware tool

Correct way to flash the BIOS:

  1. Determine current version
    -> msinfo32
    -> Dxdiag
    -> Will be able to check out our current BIOS version
  2.  Find the correct update on the manufacturers website
    -> Download current BIOS version and the newest BIOS version if we want to reload the old version
  3. Secure our power source
    -> Updating the firmware on the BIOS and experiencing a power loss, it corrupt the firmware on the BIOS
    -> Backup electric power, not plugged in directly into the wall but into a UPS (uninterruptable power supply)
    -> Plug this UPS into the wall which charges itself with electricity
    -> When fully charged, we can plug our computer into it and receive its energy if we experience a power loss
    -> Laptops come with built-in battery pack, so we just have to plug it into the wall
  4. Install BIOS / Flash BIOS
    -> Go through the recommended steps of the manufacturer

NotepadBIOS - Component Information

Location of the BIOS on the motherboard:
-> Round CMOS battery (Complementary metal-oxide-semiconductor) provides constant power to the semiconductor; works in conjunction with the BIOS as backup energy
-> BIOS close by the CMOS battery
-> Held in on all four size and has the firmware printed on it

Information provided by the BIOS:

  • Enter into the BIOS: Blick F1 on startup (button depends on computer)
  • Check out component information
    • RAM – how much is installed/available, which slots are used/open on the motherboard, amounts of information depend on BIOS version
    • Hard Drive – amount of installed hard drives, where are they attached on the mother board, options to change booting if multiple operating systems are installed
    • Optical Drive – CD, Blu-Ray, ..
    • CPU – manufacturer, type of CPU, speed and caching rate, options to change properties

NotepadBIOS Configurations

In addition to providing the information about the computer, the BIOS allows the user to change and configure the components -> will be saved on the CMOS battery

  • Boot configuration – order of operating systems for the computer to start from 
    • Hard drive 
    • CD
    • USB
    • PXE (PXE booting/network booting), i.e. reimage computer from the network by connecting to an imaging server (default disabled sometimes)
  • Enabling/disabling devices
    • I/O devices conntected to the computer, i.e. external USB port, sound cards or disk drives
    • WOL (Wake On Lan) – enable WOL in order to remotely start a computer even if it is turned off
    • Date/Time
    • CPU clock speed – important for overclocking or performance issues but can result in other problems like overheating 
      • Just for intense using, sometimes gaming but requires a lot of research and specific research for the specific CPU
    • Virtualization – if virtualization is turned off in BIOS, it may be a problem to run virtual environments (like VirtualBox) on the computer

NotepadBIOS Diagnostics

Power On Selftest (POST)

  • performed when starting a computer
  • Set of instructions the BIOS executes to check different components of the computer that it needs in order to turn on 
  • POST completely stops when it cannot pass a step without problems with according error codes
  • In a sequential order
    • CPU & POST BIOS ROM (information on the BIOS to run the POST)
      • Check the CPU that it can be started and process information
      • Booting stops if problem will be found
    • System timer
    • Video card
      • Will allow us to see output
    • Memory (RAM)
      • Will temporarily hold information for the computer
    • Key board
    • Disk drives

How to detect errors during the POST?

  • Computer gives beeps to show that errors have occurred
    • Beeps produced on the motherboard (depends on the manufacturer)
    • Beeps are not consistent across different motherboards
  • Error codes on the screen
    • Can only show up if video card has been initialised
  • POST card
    • Can be plugged into the computer into PCI slot
    • When the computer gets turned on, it will present red codes with information about the POST
    • Not plugged in all the day, just a diagnostic tool

BIOS’ own diagnostics:

  • Depends on the BIOS if they are available
  • Go into setup 
    • Options to run certains test before the computer starts up
      • Memory test, video test, hard drive test, ..
  • Can be useful depending on the situation, especially if other options do not help to find the error


NotepadBIOS Security

Protect computer/BIOS from external threads (like theft) 
-> lock down that BIOS!

BIOS Security Options

  • S-Password / U-Password
    • Supervisor password as ultimate authority
    • User password
      • Is given permissions by the supervisor
  • Lojac (LoJack)
    • Software that is installed on the operating system
    • Persistence module in the BIOS
    • Helps to locate the stolen computer the next time it is connected to the internet / based on IP-adress
    • Option to remotely erase information on the computer
  • TPM – Trusted Platform Module
    • Chip information on the BIOS
    • Holds security keys and encryption keys
    • Can be used to encrypt passwords and information
    • Keys are stored encrypted on the BIOS
    • A lot of new computers have this option
    • Requirement for some applications like BitLocker


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