How to Bypass BIOS Passwords

How to Bypass BIOS Passwords

BIOS passwords can add an extra layer of security for desktop and laptop computers. They are used to either prevent a user from changing the BIOS settings or to prevent the PC from booting without a password. Unfortunately, BIOS passwords can also be a liability if a user forgets their password, or changes the password to intentionally lock out the corporate IT department. Sending the unit back to the manufacturer to have the BIOS reset can be expensive and is usually not covered in the warranty. Never fear, all is not lost. There are a few known backdoors and other tricks of the trade that can be used to bypass or reset the BIOS

DISCLAIMER
This article is intended for IT Professionals and systems administrators with experience servicing computer hardware. It is not intended for home users, hackers, or computer thieves attempting to crack the password on a stolen PC. Please do not attempt any of these procedures if you are unfamiliar with computer hardware, and please use this information responsibly. LabMice.net is not responsible for the use or misuse of this material, including loss of data, damage to hardware, or personal injury.


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. In the event the manufacturer cannot (or will not) help you, there are a number of methods that can be used to bypass or reset the BIOS password yourself. They include:

Using a manufacturers backdoor password to access the BIOS

Use password cracking software

Reset the CMOS using the jumpers or solder beads.

Removing the CMOS battery for at least 10 minutes

Overloading the keyboard buffer

Using a professional service

Please remember that most BIOS passwords do not protect the hard drive, so if you need to recover the data, 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.


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Backdoor passwords

Many BIOS manufacturers have provided backdoor passwords that can be used to access the BIOS setup in the event you have lost your password. These passwords are case sensitive, so you may wish to try a variety of combinations. Keep in mind that the key associated to "_" in the US keyboard corresponds to "?" in some European keyboards. Laptops typically have better BIOS security than desktop systems, and we are not aware of any backdoor passwords that will work with name brand laptops.

WARNING: 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

Award BIOS backdoor passwords:

ALFAROME ALLy aLLy aLLY ALLY aPAf _award AWARD_SW AWARD?SW AWARD SW AWARD PW AWKWARD awkward BIOSTAR CONCAT CONDO Condo d8on djonet HLT J64 J256 J262 j332 j322 KDD Lkwpeter LKWPETER PINT pint SER SKY_FOX SYXZ syxz shift + syxz TTPTHA ZAAADA ZBAAACA ZJAAADC 01322222
589589 589721 595595 598598

AMI BIOS backdoor passwords:

AMI AAAMMMIII BIOS PASSWORD HEWITT RAND AMI?SW AMI_SW LKWPETER A.M.I. CONDO

PHOENIX BIOS backdoor passwords:

phoenix, PHOENIX, CMOS, BIOS

MISC. COMMON PASSWORDS

ALFAROME BIOSTAR biostar biosstar CMOS cmos LKWPETER lkwpeter setup SETUP Syxz Wodj

OTHER BIOS PASSWORDS BY MANUFACTURER

Manufacturer 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
TMC BIGO
Toshiba Toshiba

TOSHIBA BIOS

Most Toshiba laptops and some desktop systems will bypass the BIOS password if the left shift key is held down during boot

IBM APTIVA BIOS

Press both mouse buttons repeatedly during the boot


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Password cracking software

The following software can be used to either crack or reset the BIOS on many chipsets. If your PC is locked with a BIOS administrator password that will not allow access to the floppy drive, these utilities may not work. Also, since these utilities do not come from the manufacturer, use them cautiously and at your own risk.

Cmos password recovery tools 3.1
!BIOS (get the how-to article)
RemPass
KILLCMOS

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Using the Motherboard "Clear CMOS" Jumper or Dipswitch settings

Many motherboards feature a set of jumpers or dipswitches that will clear the CMOS and wipe all of the custom settings including BIOS passwords. The locations of these jumpers / dipswitches will vary depending on the motherboard manufacturer and ideally you should always refer to the motherboard or computer manufacturers documentation. If the documentation is unavailable, the jumpers/dipswitches can sometimes be found along the edge of the motherboard, next to the CMOS battery, or near the processor. Some manufacturers may label the jumper / dipswitch CLEAR - CLEAR CMOS - CLR - CLRPWD - PASSWD - PASSWORD - PWD. On laptop computers, the dipswitches are usually found under the keyboard or within a compartment at the bottom of the laptop.
Please remember to unplug your PC and use a grounding strip before reaching into your PC and touching the motherboard. Once you locate and rest the jumper switches, turn the computer on and check if the password has been cleared. If it has, turn the computer off and return the jumpers or dipswitches to its original position.


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Removing the CMOS Battery

The CMOS settings on most systems are buffered by a small battery that is attached to the motherboard. (It looks like a small watch battery). If you unplug the PC and remove the battery for 10-15 minutes, the CMOS may reset itself and the password should be blank. (Along with any other machine specific settings, so be sure you are familiar with manually reconfiguring the BIOS settings before you do this.) Some manufacturers backup the power to the CMOS chipset by using a capacitor, so if your first attempt fails, leave the battery out (with the system unplugged) for at least 24 hours. Some batteries are actually soldered onto the motherboard making this task more difficult. Unsoldering the battery incorrectly may damage your motherboard and other components, so please don't attempt this if you are inexperienced. Another option may be to remove the CMOS chip from the motherboard for a period of time.
Note: Removing the battery to reset the CMOS will not work for all PC's, and almost all of the newer laptops store their BIOS passwords in a manner which does not require continuous power, so removing the CMOS battery may not work at all. IBM Thinkpad laptops lock the hard drive as well as the BIOS when the supervisor password is set. If you reset the BIOS password, but cannot reset the hard drive password, you may not be able to access the drive and it will remain locked, even if you place it in a new laptop. IBM Thinkpads have special jumper switches on the motherboard, and these should be used to reset the system.


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Overloading the KeyBoard Buffer

On some older computer systems, you can force the CMOS to enter its setup screen on boot by overloading the keyboard buffer. This can be done by booting with the keyboard or mouse unattached to the systems, or on some systems by hitting the ESC key over 100 times in rapid succession.


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Jumping the Solder Beads on the CMOS

It is also possible to reset the CMOS by connecting or "jumping" specific solder beads on the chipset. There are too many chipsets to do a breakdown of which points to jump on individual chipsets, and the location of these solder beads can vary by manufacturer, so please check your computer and motherboard documentation for details. This technique is not recommended for the inexperienced and should be only be used as a "last ditch" effort.


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Using a professional service

If the manufacturer of the laptop or desktop PC can't or won't reset the BIOS password, you still have the option of using a professional service. Password Crackers, Inc., offers a variety of services for desktop and laptop computers for between $100 and $400. For most of these services, you'll need to provide some type of legitimate proof of ownership. This may be difficult if you've acquired the computer second hand or from an online auction.

Reset your BIOS password

Here's a DOS trick for Windows 9x, that will reset (delete) your motherboard's BIOS password (aka CMOS password) without any need to open up your computer to remove the battery or mess with jumpers.

This method can come in very handy in the event you ever lose and forget your BIOS password or if you acquire used computers where the unknown previous owners had BIOS passwords set (in fact, this happened to me long ago—I was given a used computer, but there was no way I could enter the CMOS to make changes). It's important to note here that the password we are talking about is only the one that prevents a user from entering the BIOS setup at bootup, not the one that stops you from getting past the boot.

Normally, at bootup you can press a key (usually the DEL key) to access your BIOS allowing you to view it or make changes. With a password set, there is no way to enter setup. Though a password can provide a basic and very effective level of PC security, losing it can be a real headache if you don't know how to fix the problem.

The MS-DOS command that will makes this trick possible is the DEBUG command (debug itself is a utility—debug.exe—which is located in your Windows Command folder). This is not a command to be taken lightly—in other words, it's not a command to play with! You can cause serious corruption with this command and can end up not being able to even boot your computer! Debug is used to work with binary and executable files and allows you to alter (hex edit) the contents of a file or CPU register right down to the binary and byte level.

To begin debug mode, type debug at a MS-DOS prompt or you can specify a file, i.e., DEBUG FILE.EXE. There is a difference in screen output between the two methods. When you type DEBUG alone, debug responds with a hyphen (-) prompt waiting for you to enter commands. The second method, with a file specified, loads the file into memory and you type all the commands on the line used to start debug. In this tip, we will be writing to the BIOS, so the first method is the one that would be used. All debug commands can be aborted at any time by pressing CTRL/C.

Accessing BIOS with DEBUG
The basic trick will be to fool the BIOS into thinking there is a checksum error, in which case it resets itself, including the password. This is done by invalidating the CMOS and to do that we must know how to access the BIOS and where the checksum value of the CMOS is located so that we can change it. Access to the the BIOS content is via what are known as CMOS Ports and it's Port 70 and 71 that will give us the needed access. On almost all AT motherboards, the checksum is located at hexadecimal address 2e and 2f and filling the address 2e with ff is all you should have to do to invalidate the checksum.

Here's what to do if you ever need to reset the password and have no other method, and you don't want to open up your computer to remove the battery or jumpers.

Note! Do this at your own risk. I can only tell you that it has worked for me more than once and has worked for others as well. But I cannot make any guarantees. When I did this, I took a willing risk. The BIOS was Award Modular BIOS v4.51PG

Restart your computer in MS-DOS mode.


When you get to the C:\> or C:\WINDOWS> prompt, type DEBUG and press Enter.


A hyphen (-) prompt will appear waiting for you to enter commands.


Enter the following commands, pressing Enter after each one. Note: the o is the letter o and stands for OUTPUT.


o 70 2e


o 71 ff


q


After the q command (which stands for QUIT), enter Exit.


Then try to enter your BIOS at bootup. The password prompt should now be gone and you should now have full access to it again. However, you will now be at the default BIOS setttings and may want to change them to your preference. You may also want to have your drives autodetected again.
In closing, I should state that in the case of a lost BIOS password, your first step should always be to contact your manufacturer to see if a backdoor password is available that will allow you to bypass the forgotten password.

There are many sites on the net that list backdoor passwords you can try, but beware that some BIOS that are set up to lock up if you enter the wrong password more than a certain number of times, usually only 3 times!