Normally, BIOS password is set to add extra security layer to prevent the sytem from unauthorized access but sometimes it may become headache if password is forgotten.

In such cases we need to bypass or clear the BIOS password.
If this is the case with you, there is no need to worry as there are many alternative ways available to set or reset the BIOS password.
some methods are as follow:

  1. By using MS DOS command
  2. By removing CMOS battery
  3. By using motherboard jumper
  4. By using software
  5. By using Backdoor BIOS password

By using MS DOS command

In this post I am going to show you the method to set/reset BIOS password. As this method requires MS-DOS, you should have access of MS-DOS during the system is on.

Follow the given steps one by one:

1.Open Command prompt from program menu or just type cmd in run window.

2.Type the following command one bye one:


o 70 2E
o 71 FF

Note: Please note that first letter in command is letter ‘o’ and not the letter ‘0’ (zero).

and that’s it. Now restart your system. It should have reset your BIOS setting and password.


  1. The first command debug is for using debug tool of MS-DOS
  2. Letter ‘o’ outputs the value to IO ports.
  3. 70 and 71 are the port numbers used to access CMOS memory.
  4. The value “FF” tells the CMOS that there is an invalid checksum so it resets the CMOS setting along with password.
  5. “quit” command is used to close the MS-DOS window.