BIOS is an acronym for Basic Input Output System.Computers BIOS is the first program that is run when the computer starts. It is a program that stores configuration details about the computer hardware and enables the computer to boot up. When the computer is switched on the BIOS loads configuration data into main memory, performs a routine diagnostic test on the hardware, then loads the operating system. The BIOS is mounted in a ROM chip, which is pleced on the motherboard,in such a way that it is removable.
CMOS (complementary metal-oxide semiconductor)is another name for a BIOS chip.
There are provisions which allows BIOS to ask for a password when it starts thus restricting access to your computer.
BIOS passwords add an extra security for desktop and laptop computers. They prevent a user from changing the BIOS settings and prevent the PC from booting without a password.
but BIOS passwords can put a user into trouble if the user forgets his password.There are a few tricks that can be used to bypass or reset the BIOS password on most systems.
Most of the BIOS passwords do not protect the hard drive, so if the data recovery is needed, simply remove the hard drive and install it in an identical system, or configure it as a slave drive in an existing system. The exception to this are laptops, especially IBM Thinkpads, which silently lock the hard drive if the supervisor password is enabled. If the supervisor password is reset without resetting the and hard drive as well, you will be unable to access the data on the drive.
Before attempting to bypass the BIOS password on a computer, please take a minute to contact the hardware manufacturer support staff directly and ask for their recommended methods of bypassing the BIOS security.
Please be cautious in using BIOS passwords as Some BIOS configurations will lock you out of the system completely if you type in an incorrect password more than 3 times. Read your manufacturers documentation for the BIOS setting before you begin typing in passwords