HOW TO BYPASS BIOS PASSWORDS
THE PROBLEM:
You had set a boot password on your computer (BIOS password) and you forgot it!
Consequence:
You cant modify your BIOS settings!
Your computer cant boot!
THE PRINCIPLE:
BIOS stands for BASIC INPUT OUTPUT SYSTEM. It is nothing but a set of procedures or programs contained in a small ROM (Read Only Memory) chipset on the motherboard of PC based computers. These procedures handle all input-output functions so that programs installed on your hard disk should not have to manipulate the hardware directly.
BIOS passwords add an extra layer of security for desktop and laptop computers. They are used to either prevent a user from accidentaly changing the BIOS settings or to prevent the computer from booting without a password. This is also a good but dangerous way of preventing unwanted users from having access to your files. It is dangerous in the sense that you might forget the password and find yourself unable to use your own computer.
DISCLAIMER:This article is mainly for information purposes, It is not intended for hackers, or computer
thieves attempting to crack the password on a stolen PC or laptop. Computer Tips and Tricks nor its authors are therefore not responsible for the use or misuse of the material presented in this article and eventual physical or logical damage that may result from its usage or misusage on your computer or yourself.
DISCLAIMER:This article is mainly for information purposes, It is not intended for hackers, or computer
thieves attempting to crack the password on a stolen PC or laptop. Computer Tips and Tricks nor its authors are therefore not responsible for the use or misuse of the material presented in this article and eventual physical or logical damage that may result from its usage or misusage on your computer or yourself.
THE SOLUTION:
There are many metods that you can use to bypass or reset the BIOS password yourself. I have listed them in increasing level of difficulty and risk so start by trying out the first method, if it does not work go to the next one and so on. One thing is sure - It is IMPOSSIBLE that after trying all methods, your problem is not solved.
The methods I will explain are:
1) Removing the CMOS battery for at least 10-15 minutes
2) Using a manufacturers backdoor password to access the BIOS
3) Using the "DEBUG" MS-Dos command
4) Using the Motherboard "Clear CMOS" Jumper or Dipswitch settings
5) Short-circuiting the BIOS chip
There are other methods but these are the best statistically.
NOTE: Remember that most BIOS passwords do not protect the hard drive, so if your only problem is to recover data from a BIOS coded computer, simply remove the hard disc drive and install it in an identical system, or configure it as a slave drive in an existing system. The exception to this rule are laptops, which most of the time silently lock the hard drive if the BIOS password is enabled. If the BIOS password is reset
without resetting the hard drive as well, you will be unable to access the data on the drive.
SOLUTION 1) Removing the CMOS Battery
This is the most easy and straight forward method and it does not require much hardware knowledge (for laptops, will require you to dismount it. If you are not comfortable with that, have it done by a pro) and is very efficient especially for desktops.
The BIOS settings on most computers are buffered (stored) by a small battery that is attached to the motherboard (The CMOS battery - which looks like a small watch battery). If you unplug the power cable of the PC and remove the battery for 10-15 minutes, it should reset itself (loose all the information it contains - including the password) so the password should be wiped out(along with any other machine specific settings such as system time and date, boot order etc.) 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 or buy a new one and put it in your computer. Below are screenshoots of sample CMOS Batteries of desktops and laptops as well as their possible locations on the motherboard.
The methods I will explain are:
1) Removing the CMOS battery for at least 10-15 minutes
2) Using a manufacturers backdoor password to access the BIOS
3) Using the "DEBUG" MS-Dos command
4) Using the Motherboard "Clear CMOS" Jumper or Dipswitch settings
5) Short-circuiting the BIOS chip
There are other methods but these are the best statistically.
NOTE: Remember that most BIOS passwords do not protect the hard drive, so if your only problem is to recover data from a BIOS coded computer, simply remove the hard disc drive and install it in an identical system, or configure it as a slave drive in an existing system. The exception to this rule are laptops, which most of the time silently lock the hard drive if the BIOS password is enabled. If the BIOS password is reset
without resetting the hard drive as well, you will be unable to access the data on the drive.
SOLUTION 1) Removing the CMOS Battery
This is the most easy and straight forward method and it does not require much hardware knowledge (for laptops, will require you to dismount it. If you are not comfortable with that, have it done by a pro) and is very efficient especially for desktops.
The BIOS settings on most computers are buffered (stored) by a small battery that is attached to the motherboard (The CMOS battery - which looks like a small watch battery). If you unplug the power cable of the PC and remove the battery for 10-15 minutes, it should reset itself (loose all the information it contains - including the password) so the password should be wiped out(along with any other machine specific settings such as system time and date, boot order etc.) 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 or buy a new one and put it in your computer. Below are screenshoots of sample CMOS Batteries of desktops and laptops as well as their possible locations on the motherboard.
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 electric power, so removing the CMOS battery may not work at all for them.
SOLUTION 2) Using manufacturer backdoor passwords
This is the second easiest method and does not need you to open your system unit.
Most BIOS manufacturers have provided backdoor passwords that can be used to access the BIOS setup in the event you have lost your password.
WARNING: Some BIOS configurations will lock you out of the system completely if you type in an incorrect password more than 3 times. If possibly read your manufacturers documentation for the BIOS settings before you begin typing in passwords and if it is their case, try solution 2 after 2 unsuccessful password trials.
The list being too long, I have compiled it in a pdf that you can download in .doc or .pdf format below.
All you need to do is identify your BIOS or Computer (System unit) manufacturer and try out the
corresponding backdoor passwords.
SOLUTION 3) Using the "DEBUG" MS-Dos command
This method clears the BIOS such that the next time you start the PC, you are not asked for any password. It does not require you to open your system unit but for you to use this method you must have access to the original DOS prompt (from the MS-DOS operating system, not from a MS-DOS shell window in Windows). That is where all the difficulty lays because on most advanced computer systems (mostly laptops) you cant boot from anything else (neither Floopy disc nor CD/DVD) without typing in the BIOS password so you will not even be able to run MS-DOS from either Floppy Disc or CD/DVD. Nevertheless on some computers you might have the possibility of doing that. If that is your case then identify your BIOS manufacturer and after opening the DOS prompt type in the commands corresponding to your BIOS manufacturer.
NOTE: Hit enter after each line of commands, at the end of the 3 lines type "exit" and hit enter then restart the machine. The BIOS ROM should have beéen cleared and the computer should boot normally.
For AMI/AWARD BIOS type
o 70 17
o 71 17
q
For PHOENIX BIOS Type
o 70 FF
o 71 17
q
For Generic BIOS or all other motherboards type
o 70 2E
o 71 FF
q
NOTE: The first letter is a "O" not the number "0".
WARNING: The methods described below are for advanced computer users, If you are not comfortable with computer hardware and if none of the 3 methods described above worked, please contact me (by comment, email or facebook page or group) or a computer hardware professional to avoid damaging your computer.
SOLUTION 4) Using the Motherboard "Clear CMOS" Jumper or Dipswitch settings (For advanced users)
The canonical way to flash the BIOS via hardware is to plug, unplug, or switch a jumper/dipswitch on the motherboard (for "switching a jumper" I mean that you find a jumper that joins the central pin and a side pin of a group of three pins, you should then unplug the jumper and then plug it to the central pin and to the pin on the opposite side, so if the jumper is normally on position 1-2, you have to put it on position 2-3, or vice versa). This jumper is most of the time located near the BIOS, but could be as well anywhere on the motherboard. To find the correct jumper/dipswitch you should read the motherboard's manual. Once you've located the correct jumper, switch it (or plug or unplug it, depending of what the manual says) while the computer is turned OFF. Then wait a couple of seconds then put the jumper back to its original position and turn the computer back on. On laptop computers, the dipswitches are usually found under the keyboard or within a compartment at the bottom of the laptop. You should then move the switch to the indicated position.
If you don't have the motherboard's manual, the jumpers may be found along the edges of the motherboard, next to the CMOS battery or near the processor and will be labelled CLEAR - CLEAR CMOS - RESET CMOS CLR - CLRPWD - PASSWD - PASSWORD - PWD or J4. Look at your motherboard attentively and you should see such a label on your motherboard with a jumper besides it. For laptops, you should test all the possible switch positions. Below are some images showing you were these jumpers can be found and their labels on the motherboard.
If you dont find any of the labels above, then you'll have to "brute force" your motherboard that is trying out all the jumpers/dipswitches of your motherboard. In this case, try first the isolated ones (those that are not in a group), the ones near to the BIOS, along the edges of the motherboard and the ones you can switch (as I explained before). If all of them fail, try all the others. However, you must modify the status of ONLY ONE
jumper at a time, otherwise you could damage the motherboard (since you don't know what the jumper you switched, plugged or unplugged is actually meant for). If the password request screen still appears, try another one until you find the good one... and you will find it, sooner or later!
If after flashing the BIOS, the computer won't boot when you turn it on, turn it off, wait for some seconds and try again.
NOTE: Remember to unplug your PC before touching the motherboard of your computer. Once you locate and remove the jumper/dipswitches, 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 their original position.
SOLUTION 5) Short-circuiting the BIOS chip
(For highly advanced users. Can irreversibly damage your computer)
Another way to clear the BIOS password is to reset it by short circuiting two pins of its chip for a few seconds. The chip looks like what is shown on the images below.
You can do that with a small piece of electric wire or with a bent paper clip.
WARNING: Always make sure that the computer is turned OFF before trying this operation.
Below is a list of EPROM chips that are commonly used in the BIOS industry. You may find similar chips with different names if they are compatible chips made by another brand. If you find the BIOS chip you are working on matches with one of the following you can try to short-circuit the appropriate pins. Once again be careful, because this operation may damage the chip and/or the computer
CHIPS P82C206 (square)
"Short together pins 12 and 32" (the first and the last pins on the bottom edge of the chip)
"or pins 74 and 75" (the two pins on the upper left corner).
OPTi F82C206 (rectangular)
"Short together pins 3 and 26" (third pin from left side and fifth pin from right side
on the bottom edge).
Dallas DS1287, DS1287A and Benchmarq bp3287MT, bq3287AMT
The Dallas DS1287 and DS1287A, and the compatible Benchmarq bp3287MT and bq3287AMT chips have a built-in battery. This battery should last up to ten years. Any motherboard using these chips should not have an additional battery (this means you can't flash the BIOS by removing a battery). When the battery fails, the RTC chip would be replaced. CMOS RAM can be cleared on the 1287A and 3287AMT chips by "shorting pins 12 and 21."
NOTE: The 1287 (and 3287MT) differ from the 1287A in that the BIOS can't be cleared.
If there is a problem such as a forgotten password, the chip must be replaced.
(In this case it is recommended to replace the 1287 with a 1287A).
Dallas DS12885S, Benchmarq bq3258S, Hitachi HD146818AP, Samsung KS82C6818A
This are rectangular 24-pin DIP chips, usually in a socket. The number on the chip should end in 6818.
Although this chip is pin-compatible with the Dallas 1287/1287A, there is no built-in battery. "Short together pins 12 and 24."
Motorola MC146818AP
"Short pins 12 and 24." These are the pins on diagonally opposite corners -
lower left and upper right. You might "also try pins 12 and 20."
If nothing above works, you could replace the existing BIOS chip with a new one, you can buy a compatible one from any computer maintenance workshop. It's a quick operation if the chip is inserted on a base and not soldered to the motherboard, otherwise you'll have to unsolder it and then put the new one (see a profesional if you are not very comfortable with soldereing).In this case, it would be more convenient to
solder a base on which you'll then plug the new chip, in the eventuality that you'll have to change it again. If you can't find the BIOS chip specifically made for your motherboard, you should buy and solder one of the same type (probably one of the ones shown above)
REMEMBER: Whatever method you use, when you flash the BIOS not only the password, but also all the other configuration data will be reset to the factory defaults, so when you are booting for the first time after a BIOS flash, you should enter the CMOS configuration menu and configure up some things (date/time, boot order, etc). Also, when you boot Windows, it may happen that it finds some new device, because of the new configuration of the BIOS, in this case you'll probably need the Windows installation CD because Windows may ask you for some external files.
Hope it helped! Stay Tuned!
For any question, suggestion, remark, request or special query please leave
a comment below with your request and email adress or
- at freecomputertipsandtricks@gmail.com
SOLUTION 2) Using manufacturer backdoor passwords
This is the second easiest method and does not need you to open your system unit.
Most BIOS manufacturers have provided backdoor passwords that can be used to access the BIOS setup in the event you have lost your password.
WARNING: Some BIOS configurations will lock you out of the system completely if you type in an incorrect password more than 3 times. If possibly read your manufacturers documentation for the BIOS settings before you begin typing in passwords and if it is their case, try solution 2 after 2 unsuccessful password trials.
The list being too long, I have compiled it in a pdf that you can download in .doc or .pdf format below.
All you need to do is identify your BIOS or Computer (System unit) manufacturer and try out the
corresponding backdoor passwords.
NOTE: If you dont know how, you can learn how to identify your computers BIOS manufacturer without having to open your system unit by reading one of my previous posts here How to fix your computer yourself !Complete list of all BIOS Beep Codes
SOLUTION 3) Using the "DEBUG" MS-Dos command
This method clears the BIOS such that the next time you start the PC, you are not asked for any password. It does not require you to open your system unit but for you to use this method you must have access to the original DOS prompt (from the MS-DOS operating system, not from a MS-DOS shell window in Windows). That is where all the difficulty lays because on most advanced computer systems (mostly laptops) you cant boot from anything else (neither Floopy disc nor CD/DVD) without typing in the BIOS password so you will not even be able to run MS-DOS from either Floppy Disc or CD/DVD. Nevertheless on some computers you might have the possibility of doing that. If that is your case then identify your BIOS manufacturer and after opening the DOS prompt type in the commands corresponding to your BIOS manufacturer.
NOTE: Hit enter after each line of commands, at the end of the 3 lines type "exit" and hit enter then restart the machine. The BIOS ROM should have beéen cleared and the computer should boot normally.
For AMI/AWARD BIOS type
o 70 17
o 71 17
q
For PHOENIX BIOS Type
o 70 FF
o 71 17
q
For Generic BIOS or all other motherboards type
o 70 2E
o 71 FF
q
NOTE: The first letter is a "O" not the number "0".
WARNING: The methods described below are for advanced computer users, If you are not comfortable with computer hardware and if none of the 3 methods described above worked, please contact me (by comment, email or facebook page or group) or a computer hardware professional to avoid damaging your computer.
SOLUTION 4) Using the Motherboard "Clear CMOS" Jumper or Dipswitch settings (For advanced users)
The canonical way to flash the BIOS via hardware is to plug, unplug, or switch a jumper/dipswitch on the motherboard (for "switching a jumper" I mean that you find a jumper that joins the central pin and a side pin of a group of three pins, you should then unplug the jumper and then plug it to the central pin and to the pin on the opposite side, so if the jumper is normally on position 1-2, you have to put it on position 2-3, or vice versa). This jumper is most of the time located near the BIOS, but could be as well anywhere on the motherboard. To find the correct jumper/dipswitch you should read the motherboard's manual. Once you've located the correct jumper, switch it (or plug or unplug it, depending of what the manual says) while the computer is turned OFF. Then wait a couple of seconds then put the jumper back to its original position and turn the computer back on. On laptop computers, the dipswitches are usually found under the keyboard or within a compartment at the bottom of the laptop. You should then move the switch to the indicated position.
If you don't have the motherboard's manual, the jumpers may be found along the edges of the motherboard, next to the CMOS battery or near the processor and will be labelled CLEAR - CLEAR CMOS - RESET CMOS CLR - CLRPWD - PASSWD - PASSWORD - PWD or J4. Look at your motherboard attentively and you should see such a label on your motherboard with a jumper besides it. For laptops, you should test all the possible switch positions. Below are some images showing you were these jumpers can be found and their labels on the motherboard.
If you dont find any of the labels above, then you'll have to "brute force" your motherboard that is trying out all the jumpers/dipswitches of your motherboard. In this case, try first the isolated ones (those that are not in a group), the ones near to the BIOS, along the edges of the motherboard and the ones you can switch (as I explained before). If all of them fail, try all the others. However, you must modify the status of ONLY ONE
jumper at a time, otherwise you could damage the motherboard (since you don't know what the jumper you switched, plugged or unplugged is actually meant for). If the password request screen still appears, try another one until you find the good one... and you will find it, sooner or later!
If after flashing the BIOS, the computer won't boot when you turn it on, turn it off, wait for some seconds and try again.
NOTE: Remember to unplug your PC before touching the motherboard of your computer. Once you locate and remove the jumper/dipswitches, 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 their original position.
SOLUTION 5) Short-circuiting the BIOS chip
(For highly advanced users. Can irreversibly damage your computer)
Another way to clear the BIOS password is to reset it by short circuiting two pins of its chip for a few seconds. The chip looks like what is shown on the images below.
You can do that with a small piece of electric wire or with a bent paper clip.
WARNING: Always make sure that the computer is turned OFF before trying this operation.
Below is a list of EPROM chips that are commonly used in the BIOS industry. You may find similar chips with different names if they are compatible chips made by another brand. If you find the BIOS chip you are working on matches with one of the following you can try to short-circuit the appropriate pins. Once again be careful, because this operation may damage the chip and/or the computer
CHIPS P82C206 (square)
"Short together pins 12 and 32" (the first and the last pins on the bottom edge of the chip)
"or pins 74 and 75" (the two pins on the upper left corner).
OPTi F82C206 (rectangular)
"Short together pins 3 and 26" (third pin from left side and fifth pin from right side
on the bottom edge).
Dallas DS1287, DS1287A and Benchmarq bp3287MT, bq3287AMT
The Dallas DS1287 and DS1287A, and the compatible Benchmarq bp3287MT and bq3287AMT chips have a built-in battery. This battery should last up to ten years. Any motherboard using these chips should not have an additional battery (this means you can't flash the BIOS by removing a battery). When the battery fails, the RTC chip would be replaced. CMOS RAM can be cleared on the 1287A and 3287AMT chips by "shorting pins 12 and 21."
NOTE: The 1287 (and 3287MT) differ from the 1287A in that the BIOS can't be cleared.
If there is a problem such as a forgotten password, the chip must be replaced.
(In this case it is recommended to replace the 1287 with a 1287A).
Dallas DS12885S, Benchmarq bq3258S, Hitachi HD146818AP, Samsung KS82C6818A
This are rectangular 24-pin DIP chips, usually in a socket. The number on the chip should end in 6818.
Although this chip is pin-compatible with the Dallas 1287/1287A, there is no built-in battery. "Short together pins 12 and 24."
Motorola MC146818AP
"Short pins 12 and 24." These are the pins on diagonally opposite corners -
lower left and upper right. You might "also try pins 12 and 20."
If nothing above works, you could replace the existing BIOS chip with a new one, you can buy a compatible one from any computer maintenance workshop. It's a quick operation if the chip is inserted on a base and not soldered to the motherboard, otherwise you'll have to unsolder it and then put the new one (see a profesional if you are not very comfortable with soldereing).In this case, it would be more convenient to
solder a base on which you'll then plug the new chip, in the eventuality that you'll have to change it again. If you can't find the BIOS chip specifically made for your motherboard, you should buy and solder one of the same type (probably one of the ones shown above)
REMEMBER: Whatever method you use, when you flash the BIOS not only the password, but also all the other configuration data will be reset to the factory defaults, so when you are booting for the first time after a BIOS flash, you should enter the CMOS configuration menu and configure up some things (date/time, boot order, etc). Also, when you boot Windows, it may happen that it finds some new device, because of the new configuration of the BIOS, in this case you'll probably need the Windows installation CD because Windows may ask you for some external files.
Hope it helped! Stay Tuned!
For any question, suggestion, remark, request or special query please leave
a comment below with your request and email adress or
- at freecomputertipsandtricks@gmail.com
- follow us on our facebook page Computer Tips and Tricks
- join our facebook group Computer Tips and Tricks
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