Break BIOS Password for Desktop Computers :

1.Power off the computer and make sure that it is unplugged.
Open up your computer case. You need physical access to the motherboard to complete this procedure.
2.Find a circular, (mostly) silver metallic object on the motherboard. This is the CMOS battery.
CAREFULLY remove the CMOS battery and leave it out for about 120- 180 seconds. This will flush the CMOS memory which stores the BIOS password and all other configuration. (See Warnings)
3.Set the battery back into place and power on the computer.
The computer should then warn you that the CMOS configuration could not be found. You can either reconfigure it yourself or restore defaults. Restoring the default configuration should be fine.
4.You will notice that the BIOS password has been cleared and you can boot without it. You may reset the BIOS password to something else by going into the BIOS configuration and setting a new User Password.