How to Remove BIOS Password

First method:

Remove the battery (cell) placed on motherboard.

Second method:

Some BIOS manufacturers implement a backdoor password. The backdoor password is a BIOS password that works, no matter what the user sets the BIOS password to. These passwords are typically used for testing and maintenance. Manufacturers typically change the backdoor BIOS passwords from time to time.
AMI Backdoor BIOS Passwords

Reported AMI backdoor BIOS passwords include A.M.I., AAAMMMIII, AMI?SW , AMI_SW, BIOS, CONDO, HEWITT RAND, LKWPETER, MI, and PASSWORD.
Award Backdoor BIOS Passwords

One reported Award backdoor BIOS password is eight spaces. Other reported Award backdoor BIOS passwords include 01322222, 589589, 589721, 595595, 598598 , ALFAROME, ALLY, ALLy, aLLY, aLLy, aPAf, award, AWARD PW, AWARD SW, AWARD?SW, AWARD_PW, AWARD_SW, AWKWARD, awkward, BIOSTAR, CONCAT, CONDO, Condo, condo, d8on, djonet, HLT, J256, J262, j262, j322, j332, J64, KDD, LKWPETER, Lkwpeter, PINT, pint, SER, SKY_FOX, SYXZ, syxz, TTPTHA, ZAAAADA, ZAAADA, ZBAAACA, and ZJAAADC.

Phoenix Backdoor BIOS Passwords

Reported Phoenix BIOS backdoor passwords include BIOS, CMOS, phoenix, and PHOENIX.
Backdoor BIOS Passwords from Other Manufacturers

Reported BIOS backdoor passwords for other manufacturers include:

Manufacturer BIOS Password
VOBIS & IBM merlin
Dell Dell
Biostar Biostar
Compaq Compaq
Enox xo11nE
Epox central
Freetech Posterie
IWill iwill
Jetway spooml
Packard Bell bell9
QDI QDI
Siemens SKY_FOX
SOYO SY_MB
TMC BIGO
Toshiba Toshiba

Remember that what you see listed may not be the actual backdoor BIOS password, this BIOS password may simply have the same checksum as the real backdoor BIOS password. For Award BIOS, this checksum is stored at F000:EC60.