Basic Input / Output System- The first and last program executed by each and every computers used today. It operates on flag system which is a mechanical language i.e. zeros and ones. It works on the flow that is designed and integrated at the time of manufacturing the motherboard. Usually the motherboard holds the ROM and ROM contain the BIOS program module.
The BIOS is initiated when power is turned on and it checks for the basic hardware components in the system to start the operating system. The operating systems are built in a way to find a specific file by the BIOS which are the map to guide the BIOS further. These programs take charge of BIOS and use it to access peripheral components like keyboard, etc.The first program initiated while using Windows is NTLDR.dll. If this file went missing or renamed, the BIOS will throw an error displaying that the needed file is missing.
Normally the BIOS is programmed in a way as non-rewritable block of code. Because it is the first program to be executed and deals directly with the hardware components; if it’s misused or damaged,the entire PC becomes useless and worth for none.
Need for BIOS update:
When PC world advances in the field of mobile storage devices and other hardware peripherals, there appears a need for an update in BIOS program.One of the necessities, some BIOS versions don’t have the support to boot from a pen drive or other external devices like memory cards and FireWire drives, which are designed and released after a very long gap after the BIOS embedded PC was purchased.
In order to overcome this problem, flashing BIOS software was introduced. It replaces the old outdated BIOS with the new one. Different motherboard manufacturers use variant software for different operating systems. Some of the tools are
Be cautious while updating
It is necessary to be cautious while using this type of software. Some tools will prompt you to purchase the full version only after deleting your current BIOS. So be wise and genuine in picking up the right tool.
How flashing BIOS tools work
You may ask that BIOS is a non – rewritable program and how come the updater tool alone can rewrite them?
The actual fact lies in the manufacture of the ROM in motherboards. They are not fully non-rewritable. The information inside a ROM can be wiped entirely and replace them with completely new one. The name ROM is made general to indicate read only memory. But the ROM can be categorized as below.
The EEPROM is the thing which is currently in use and is called as ROM in general. These EEPROM’s can be erased and coded fresh with help of electric charges. The maximum charge is attained by a PC to erase or write a program module in BIOS.
CMOS vs. BIOS
Usually it is confused that CMOS and BIOS are same. Though 60% of the statement is true, the other 40% is controversy. BIOS contains the program code which is to be executed at the time of power flow in the PC. CMOS (Complementary Meta Oxide Semiconductor) is also initiated at the time of booting, but it stores the system settings needed for the boot. This may include things like system date and time, first boot device, boot password, voltage power settings of RAM, etc.
These CMOS settings are stored in a battery called CMOS battery where the settings can be set to default by removing or replacing the CMOS battery.
The system can boot even without a CMOS battery, but definitely not without BIOS ROM.