How to clear an unknown BIOS password  

just turn of the pc and put off the cmos battery on the pc it will give u the bips and again turn of the pc and reattached the battery and turn on the pc

it wil clear the bios password
good luck

Answered by Sunil Bhogle at 6:32 PM on May 29, 2008

hello jks All you need to do is simply open the cabinate find the battry usually near to the battry you will find a jumper just remove it and put it next to the pins from where you have taken it out and remove the battery and ram for some time and then put back every thing except jumper and start the system it will give an error and in end write default settings reloded.There your job is done.
this is taken from source http://forums.microsoft.com/SamVaad /ShowPost.aspx?PostID=1684542&SiteI D=43

Answered by laks at 4:42 PM on May 16, 2008

If you cannot access the machine after if has been powered up, it is still possible to get past the BIOS password. The BIOS password is stored in CMOS memory that is maintained while the PC is powered off by a small battery, which is attached to the motherboard. If you remove this battery, all CMOS information (including the BIOS password) will be lost. You will need to re-enter the correct CMOS setup information to use the machine. The machines owner or user will most likely be alarmed when it is discovered that the BIOS password has been deleted.

On some motherboards, the battery is soldered to the motherboard, making it difficult to remove. If this is the case, you have another alternative. Somewhere on the motherboard you should find a jumper that will clear the BIOS password. If you have the motherboard documentation, you will know where that jumper is. If not, the jumper may be labeled on the motherboard. If you are not fortunate enough for either of these to be the case, you may be able to guess which jumper is the correct jumper. This jumper is usually standing alone near the battery. If you cannot locate this jumper, you might short both of the points where the battery connects to the motherboard.

If all else fails, you may have to clear the BIOS password by resetting the RTC (Real Time Clock) IC (Integrated Circuit) on your motherboard.

Many RTC's require an external battery. If your RTC is one of this type, you can clear the BIOS password just by unsocketing the RTC and reseating it.

RTC's which require external batteries include:

* Dallas Semiconductor DS12885S
* TI benchmarq bq3258S
* Motorola MC146818AP
* Hitachi HD146818AP
* Samsung KS82C6818A

Most RTC chips with integrated batteries can be reset to clear the BIOS password by shorting two pins together for a few seconds.

You will see more than one option for some chips due to testing by various people in the field. Remember to remove power from the system before shorting these pins.

RTC Chip Pins
Dallas DS1287A
TI benchmarq bp3287AMT 3 (N.C.) and 21 (NC/RCL)
Chips & Technologies P82C206 12 (GND) and 32 (5V)
-or-
74 (GND) and 75 (5V)
OPTi F82C206 3 and 26
Dallas Semiconductor DS12887A 3 (N.C.) and 21 (RCLR)

You should be able to discover how to reset the BIOS password stored in most RTC (Real Time Clock) chips by reading the manufacturers data sheet for that RTC. Some RTC's, like the Dallas DS1287 and TI benchmarq bq3287mt cannot be cleared. The solution to resetting the BIOS password on systems with those RTC's is to purchase a replacement RTC chip.

Answered by Reeta K at 5:01 PM on May 10, 2008

If you have mistakenly forgot or lost your BIOS password or you receive a password at boot that you do not know, you will need to clear the BIOS password by one of the below methods.
Precaution: When inside the computer please be sure of the potential of ESD.
Try using generic BIOS passwords. A complete listing of these passwords can be found on document CH000451.
There are utilities designed to help bypass BIOS passwords. An example of a great utility to decrypt / bypass BIOS passwords is the PC BIOS Security and Maintenance toolkit, which is available by clicking here.
On the computer motherboard locate the BIOS clear / password jumper or dipswitch and change its position. Once this jumper has been changed, turn on the computer and the password should be cleared. Once cleared, turn the computer off and return the jumper or dipswitch to its original position.
The location of the jumpers or dipswitches may vary; however, here are general locations where these jumpers / dipswitch may be located.
On the edge of the motherboard - Most jumpers are located on the side of the motherboard for easy accessibility, verify by looking at all visible edges of the motherboard.
By the CMOS battery - Some manufactures will place the jumper to clear the CMOS / BIOS password by the actual CMOS battery.
By the processor - Some manufactures will place the jumpers by the processor of the computer. However, note that in some cases these jumpers will be to change the processor and not the password.
Under the keyboard or bottom of laptop - If you are working on a laptop computer the location of the dipswitch (almost never a jumper) can be under the keyboard or on the bottom of the laptop in a compartment such as the memory compartment.
Other visible location - While it is possible that the jumpers / dipswitches may not be in a visible location, most manufactures try to make things easier by placing the jumpers / dipswitches in another visible location.
Additionally, when looking for the jumper / dipswitch the label of that switch can be anything; however, in most cases will be labeled CLEAR - CLEAR CMOS - CLR - CLRPWD - PASSWD - PASSWORD - PWD.
Sources:
http://www.xmission .com/~comphope/issues/ch000235.htm

Answered by ayisha at 6:59 PM on May 09, 2008

Precaution: When inside the computer please be sure of the potential of ESD.

* Try using generic BIOS passwords. A complete listing of these passwords can be found on document : http://www.computerhope.com/is sues/ch000451.htm
* There are utilities designed to help bypass BIOS passwords. An example of a great utility to decrypt / bypass BIOS passwords is the PC BIOS Security and Maintenance toolkit, which is available by clicking here.
* On the computer motherboard locate the BIOS clear / password jumper or dipswitch and change its position. Once this jumper has been changed, turn on the computer and the password should be cleared. Once cleared, turn the computer off and return the jumper or dipswitch to its original position.

The location of the jumpers or dipswitches may vary; however, here are general locations where these jumpers / dipswitch may be located.

1. On the edge of the motherboard - Most jumpers are located on the side of the motherboard for easy accessibility, verify by looking at all visible edges of the motherboard.
2. By the CMOS battery - Some manufactures will place the jumper to clear the CMOS / BIOS password by the actual CMOS battery.
3. By the processor - Some manufactures will place the jumpers by the processor of the computer. However, note that in some cases these jumpers will be to change the processor and not the password.
4. Under the keyboard or bottom of laptop - If you are working on a laptop computer the location of the dipswitch (almost never a jumper) can be under the keyboard or on the bottom of the laptop in a compartment such as the memory compartment.
5. Other visible location - While it is possible that the jumpers / dipswitches may not be in a visible location, most manufactures try to make things easier by placing the jumpers / dipswitches in another visible location.

Additionally, when looking for the jumper / dipswitch the label of that switch can be anything; however, in most cases will be labeled CLEAR - CLEAR CMOS - CLR - CLRPWD - PASSWD - PASSWORD - PWD.

* On the computer motherboard locate and remove the CMOS battery for at least 10 minutes allowing the computer to lose its information. Note: this will not work on all computers.
* If your manufacturer has a bypass password this can be entered and allow you access to the BIOS and/or computer. Because of the security risk of a bypass password, generally only older computers will have this option. In addition, it is likely that this information will only be able to be obtained from the computer, motherboard or BIOS manufacturer.
* On the computer motherboard locate the CMOS solder beads and jump the solder beads to clear the password. The identification and location of these solder beads can vary and if not available in computer documentation is generally only obtainable through the computer manufacturer.

If one of the above solutions do not clear the password or you are unable to locate the jumpers or solder beads, it is recommended you contact the computer manufacturer or motherboard manufacturer for the steps on clearing the computer password.

Answered by Sharad Singh at 6:50 PM on May 09, 2008

hi, its so simple to clear unknown bios password, just open your cpu then remove the litinum battery [ battry cell ] which is on your cpu then put it again, your bios password would automatically lost.

Answered by Dinesh at 1:08 PM on May 09, 2008

well jks If you cannot access the machine after if has been powered up, it is still possible to get past the BIOS password. The BIOS password is stored in CMOS memory that is maintained while the PC is powered off by a small battery, which is attached to the motherboard. If you remove this battery, all CMOS information (including the BIOS password) will be lost. You will need to re-enter the correct CMOS setup information to use the machine. The machines owner or user will most likely be alarmed when it is discovered that the BIOS password has been deleted.

On some motherboards, the battery is soldered to the motherboard, making it difficult to remove. If this is the case, you have another alternative. Somewhere on the motherboard you should find a jumper that will clear the BIOS password. If you have the motherboard documentation, you will know where that jumper is. If not, the jumper may be labeled on the motherboard. If you are not fortunate enough for either of these to be the case, you may be able to guess which jumper is the correct jumper. This jumper is usually standing alone near the battery. If you cannot locate this jumper, you might short both of the points where the battery connects to the motherboard.

If all else fails, you may have to clear the BIOS password by resetting the RTC (Real Time Clock) IC (Integrated Circuit) on your motherboard.

Many RTC's require an external battery. If your RTC is one of this type, you can clear the BIOS password just by unsocketing the RTC and reseating it.

RTC's which require external batteries include:

* Dallas Semiconductor DS12885S
* TI benchmarq bq3258S
* Motorola MC146818AP
* Hitachi HD146818AP
* Samsung KS82C6818A

Most RTC chips with integrated batteries can be reset to clear the BIOS password by shorting two pins together for a few seconds.

You will see more than one option for some chips due to testing by various people in the field. Remember to remove power from the system before shorting these pins.

RTC Chip Pins
Dallas DS1287A
TI benchmarq bp3287AMT 3 (N.C.) and 21 (NC/RCL)
Chips & Technologies P82C206 12 (GND) and 32 (5V)
-or-
74 (GND) and 75 (5V)
OPTi F82C206 3 and 26
Dallas Semiconductor DS12887A 3 (N.C.) and 21 (RCLR)

You should be able to discover how to reset the BIOS password stored in most RTC (Real Time Clock) chips by reading the manufacturers data sheet for that RTC. Some RTC's, like the Dallas DS1287 and TI benchmarq bq3287mt cannot be cleared. The solution to resetting the BIOS password on systems with those RTC's is to purchase a replacement RTC chip. How inconvenient!

Answered by sujata at 12:57 PM on May 09, 2008

well, you will need to clear the BIOS password by one of the below methods.
Precaution: When inside the computer please be sure of the potential of ESD.
Additionally, when looking for the jumper / dipswitch the label of that switch can be anything; however, in most cases will be labeled CLEAR - CLEAR CMOS - CLR - CLRPWD - PASSWD - PASSWORD - PWD.

* On the computer motherboard locate and remove the CMOS battery for at least 10 minutes allowing the computer to lose its information. Note: this will not work on all computers.
* If your manufacturer has a bypass password this can be entered and allow you access to the BIOS and/or computer. Because of the security risk of a bypass password, generally only older computers will have this option. In addition, it is likely that this information will only be able to be obtained from the computer, motherboard or BIOS manufacturer.
* On the computer motherboard locate the CMOS solder beads and jump the solder beads to clear the password. The identification and location of these solder beads can vary and if not available in computer documentation is generally only obtainable through the computer manufacturer.

If one of the above solutions do not clear the password or you are unable to locate the jumpers or solder beads, it is recommended you contact the computer manufacturer or motherboard manufacturer for the steps on clearing the computer password.

Source site: http://www.computerhope.com/is sues/ch000235.htm

Answered by Saurabh at 9:06 AM on May 09, 2008

* Try using generic BIOS passwords.
* There are utilities designed to help bypass BIOS passwords. An example of a great utility to decrypt / bypass BIOS passwords is the PC BIOS Security and Maintenance toolkit.
* On the computer motherboard locate the BIOS clear / password jumper or dipswitch and change its position. Once this jumper has been changed, turn on the computer and the password should be cleared. Once cleared, turn the computer off and return the jumper or dipswitch to its original position.
* On the computer motherboard locate and remove the CMOS battery for at least 10 minutes allowing the computer to lose its information. Note: this will not work on all computers.
* If your manufacturer has a bypass password this can be entered and allow you access to the BIOS and/or computer. Because of the security risk of a bypass password, generally only older computers will have this option. In addition, it is likely that this information will only be able to be obtained from the computer, motherboard or BIOS manufacturer.

Answered by baby singh at 9:48 PM on May 08, 2008

Shutdown your PC. Unplug the power from the wall socket. Open the cabinet. You cannot miss the silver colored battery in the motherboard. Remove the battery gently. Put it back after a minute or so. Your password will be cleared. That's it

Answered by vbster at 9:01 PM on May 08, 2008