Many people are confused about CMOS and BIOS thinking that they are the same. There is actually a huge difference between CMOS and BIOS, so you may want to get it right to prevent saying the wrong thing especially when you’re in an interview for a new job. BIOS is actually a chip on the motherboard containing a program that communicates with the CPU and other parts of the system. The BIOS program cannot be configured but can be updated through flashing the firmware provided by the manufacturer. As for CMOS, it is another chip that keeps the configurable information which is read by the BIOS. If you look carefully at the top of the screen after accessing the Setup by pressing F2/F10/F12/Del key, it actually says CMOS Setup Utility but not BIOS setup.
However the user and supervisor password that we can set to prevent unauthorized people from accessing the CMOS setup or to change the boot sequence is listed under BIOS Security Features according to AMI BIOS on my Dell computer. So I guess it is acceptable to say setting a BIOS password. Two of the most common and known old school methods to reset BIOS password is by switching the reset CMOS jumper or removing the battery from the motherboard. You can also reset BIOS password directly from Windows using a tool called CMOS De-Animator.
If you are unable to open the computer case because it is a laptop, don’t want to get your hands dirty, or for some weird reason CMOS De-Animator doesn’t work, here is another method to reset BIOS password which I am very sure that it would work because I have personally tested it.
Recently I came across two commands that claims to reset BIOS password when it is typed on the debug tool that is built-in to Windows.
o 70 2E
o 71 FF
I ran the two commands above from debug.exe under Administrator rights in Windows 7 SP1 32-bit but sadly it does not work. After researching further about this method on the Internet, it seems to be widely posted but none have verified if it is truly working or if there are additional steps required. If you’ve been reading our articles, you would have realized that we normally take a step further to test and make sure that it is working rather than just for the sake of posting something on the blog.
After much testing, I found that it is possible to reset BIOS password by typing the two commands in debug tool if you first boot up the computer in FreeDOS. Here are the detailed step-by-step instructions.
1. Install FreeDOS in a USB flash drive using Rufus or UNetbootin.
2. Download the debug.exe tool and save it to the root of your USB flash drive.
3. Boot up the computer with your USB flash drive and type the following commands: (take note that the second and third command starts with the letter O and not the number zero.
debug
o 70 2E
o 71 FF
quit
4. Restart your computer by simultaneously pressing Ctrl + Alt + Del and you would probably encounter error messages like CMOS checksum error which is normal. You can now access the CMOS setup without a password.
The above method seems to be a perfect solution but what if you cannot change the boot sequence to boot up the computer from USB flash drive and it is set to only boot from the hard drive? Obviously you cannot do anything about it since the BIOS is locked out and you cannot get in the CMOS Setup Utility to change the boot order. Well not really. With a third party boot manager called Plop which I have reviewed before, it does the impossible by booting up your computer through USB or CD/DVD even if the BIOS does not support it.
1. Boot up the computer and log in to Windows.
2. Download Plop Boot Manager
3. Extract the downloaded Plop Boot Manager, go to the Windows folder, right click on InstallToBootMenu.bat and select Run as administrator.
4. A command prompt window will open asking you to confirm adding the Plop Boot Manager to the Windows boot menu. Press the Y key and hit Enter. Then press any key to close the command prompt window.
5. Connect the USB flash drive containing the FreeDOS and debug.exe utility which you have created based on the previous step-by-step instructions.
6. Now restart your computer and select Plop Boot Manager from the Windows Boot Manager.
7. Select USB from the starfield screen and the computer will amazingly boot up FreeDOS from the USB flash drive.
Now go ahead and run the debug tool followed by the 2 commands to reset BIOS password. To remove Plop Boot Manager from the Windows Boot Manager after you have successfully reset BIOS password, simply download and install EasyBCD, run it, click the Edit Boot Menu button and delete Plop Boot Manager from the list by selecting it with your mouse and click the Delete button.
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