The best method for resetting a
Some BIOSs allow the user to require a password before the system will boot or before the BIOS setup may be accessed.
The general solution categories to reset a BIOS password are:
- Using a Backdoor BIOS Password
- Resetting the BIOS Password using Software
- Resetting the BIOS Password using Hardware
- Vendor Specific Solutions for resetting the BIOS Password
Using a Backdoor BIOS PasswordSome BIOS manufacturers implement a backdoor password. The backdoor password is a BIOS password that works no matter what the BIOS password is set to. These passwords are typically used for testing and maintenance. Manufacturers typically change the backdoor BIOS passwords from time to time.
AMI Backdoor BIOS PasswordsReported AMI backdoor BIOS passwords include A.M.I., AAAMMMIII, AMI?SW , AMI_SW, BIOS, CONDO, HEWITT RAND, LKWPETER, MI, and PASSWORD.
Award Backdoor BIOS PasswordsOne reported Award backdoor BIOS password is eight spaces. Other reported Award backdoor BIOS passwords include 01322222, 589589, 589721, 595595, 598598 , ALFAROME, ALLY, ALLy, aLLY, aLLy, aPAf, award, AWARD PW, AWARD SW, AWARD?SW, AWARD_PW, AWARD_SW, AWKWARD, awkward, BIOSTAR, CONCAT, CONDO, Condo, condo, d8on, djonet, HLT, J256, J262, j262, j322, j332, J64, KDD, LKWPETER, Lkwpeter, PINT, pint, SER, SKY_FOX, SYXZ, syxz, TTPTHA, ZAAAADA, ZAAADA, ZBAAACA, and ZJAAADC.
Phoenix Backdoor BIOS PasswordsReported Phoenix BIOS backdoor passwords include BIOS, CMOS, phoenix, and PHOENIX.
Backdoor BIOS Passwords from Other ManufacturersReported BIOS backdoor passwords for other manufacturers include:
Remember that the passwords listed may not be the actual backdoor BIOS passwords. These backdoor BIOS passwords may simply have the same checksum as the real ones. For Award BIOS, this checksum is stored at F000:EC60.
Manufacturer BIOS 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 SOYO SY_MB TMC BIGO Toshiba Toshiba
Resetting the BIOS Password with SoftwareEvery system must store the BIOS password information somewhere. If the user can access the machine after it has been booted successfully, he/she may be able to view the BIOS password. He/she must know the memory address where the BIOS password is stored and the format in which the BIOS password is stored or have a program that knows these things.
Users can write their own program to read the BIOS password from the CMOS memory on a PC by writing the address of the byte of CMOS memory that they wish to read in port 0×370, then reading port 0×371′s contents.
!BIOS recovers the BIOS password for most common BIOS versions, including IBM, American Megatrends Inc., Award, and Phoenix.
CmosPwd recovers the BIOS password for the following BIOS versions:
- ACER/IBM BIOS
- AMI BIOS
- AMI WinBIOS 2.5
- Award 4.5x/4.6x/6.0
- Compaq (1992)
- Compaq (New version)
- IBM (PS/2, Activa, Thinkpad)
- Packard Bell
- Phoenix 1.00.09.AC0 (1994), a486 1.03, 1.04, 1.10 A03, 4.05 rev 1.02.943, 4.06 rev 1.13.1107
- Phoenix 4 release 6 (User)
- Gateway Solo – Phoenix 4.0 release 6
- Zenith AMI
Resetting the BIOS Password via HardwareIf a user cannot access the machine after it has been powered up, it is still possible to get past the BIOS password. The BIOS password is stored in CMOS memory that a small battery maintains while the PC is off, which is attached to the motherboard. If the user removes this battery, all CMOS information (including the BIOS password) will be lost. The user must re-enter the correct CMOS setup information to use the machine. The machine’s owner or user will most likely be alarmed when he/she discovers that the BIOS password has been deleted.
The battery is soldered to some motherboards, making it difficult to remove. If this is the case, there is another alternative. Somewhere on the motherboard is a jumper that will clear the BIOS password. If the user has the motherboard documentation, he/she will know where that jumper is. If not, the jumper may be labeled on the motherboard. If neither of these is the case, try guessing which jumper is the correct one. This jumper is usually standing alone near the battery. If the user cannot locate the jumper, he/she might short both of the points where the battery connects to the motherboard.
If all else fails, clear the BIOS password by resetting the RTC (Real Time Clock) IC (Integrated Circuit) on the motherboard.
Many RTCs require an external battery. If so, clear the BIOS password by removing the RTC from the socket and reseating it.
RTCs that require external batteries include:
- Dallas Semiconductor DS12885S
- TI benchmarq bq3258S
- Motorola MC146818AP
- Hitachi HD146818AP
- Samsung KS82C6818A
There are a few options for some chips due to the testing that various people in the field have carried out. Remember to remove power from the system before shorting these pins.
Users should be able to figure out how to reset the BIOS password stored in most RTC (Real Time Clock) chips by reading the manufacturers data sheet for that RTC. Some RTCs, like the Dallas DS1287 and TI benchmarq bq3287mt, cannot be cleared. The solution for resetting the BIOS password on systems with those RTCs is to purchase a replacement RTC chip.
RTC Chip Pins Dallas DS1287ATI 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)
Vendor Specific Solutions for Resetting the BIOS Password
Resetting a Dell BIOS PasswordFor information on how to recover a
Resetting a Toshiba BIOS PasswordKeyDisk resets the BIOS password on Toshiba laptops.
Older Toshiba laptops can boot without their power-on BIOS password if a dongle is attached to the parallel port that crosses a number of pins. The pin out is:
Some Toshibas can bypass the startup BIOS password if the user holds down the key while booting the system.
Pins 1-5-10 2-11 3-17 4-12 6-16 7-13 8-14 9-15
Resetting an IBM Aptiva BIOS PasswordSome IBM Aptivas can bypass the startup BIOS password if both mouse buttons are pressed repeatedly while booting the system.
Resetting an Acer BIOS PasswordFor information on how to recover an Acer BIOS password, please refer to How to reset Acer BIOS Password.
Guide taken from www.tech-faq.com