with console access by erckgillis on June 15, 2007 Table of Contents intro: Bypass BIOS Boot or OS Login to "most" any computer .... By modifying the BIOS or "Flash'ing" new BIOS you can
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Bypass BIOS Boot or OS Login to "most" any computer with console
access
by erckgillis on June 15, 2007
Table of Contents
intro: Bypass BIOS Boot or OS Login to "most" any computer with console access 2
step 1: Console Access this is essential to browse files 3
step 2: Windows ISO Boot disc(s) 4
step 3: Live CD distributions to choose from (list) 4
step 4: Browse any files NTFS FAT file systems (folders) 9
step 5: Protection ? 9
step 6: BIOS Backdoors 10
Related Instructables 11
Advertisements 11
Customized Instructable T-shirts 11
Comments 11
Trang 2intro: Bypass BIOS Boot or OS Login to "most" any computer with console access
ANY system where you have access to it's console will give you an opportunity to where you can login and see files, run your own browser or copy files By modifying the BIOS or "Flash'ing" new BIOS you can override both BIOS protected passwords and reboot from other devices or peripherials Reboot with any OS you choose and browse NTFS (via http://www.ntfs-linux.com/) or FAT files on their 'secured' hard drive
Internet Cafe', Public Library and Schools with "locked" PC's are usually accessible
If you can MODIFY the BIOS to boot from USB, CD or DVD
Insert your USB Boot image (ISO) How See my instructables
Beginners Background:
The BIOS (Basic Input-Output System) is a small piece of code 'burned' into a EPROM/CMOS (Erasable Programmable Read Only Memory) This is the hard coded instructions to "boot" your PC
Even "locking" the BIOS is no longer safe as "Flash" programs can 'reprogram' most any BIOS Shorts or restes can 'fry' and many sites offer replacements/swaps File systems:
Computers all have files File systems are the way data is encoded on the hard drive It's not encrypted nor protected except for EFS or secured shadowed and hidden file systems using triple DES and PGP
Steps:
Press F2 or F10 as the reboot prompt asks
Modify as below the "Boot order"
Insert a CD/DVD or USB boot drive and your in!
(see instructables for ISo images or USB thumb drive)
Image Notes
1 Boot a DSL linux image from USB
Trang 3step 1: Console Access this is essential to browse files
Windows Computers are designed to not allow remote access Firewalls, port stealthing and all the fancy software secures you from outside and network attacks
No one protects their consoles or laptops nowadays
Do you have access to a schools computer, library or Internet Cafe' ?
Then you can load and boot many OS and see files on their HDD
Once the BIOS (bypass BIOS passwords on page 6) is set to boot from other media (USB/CD/DVD) you can load you OWN OS and login
forget Windows security load your OWN OS!
Load a small Linux or other OS, fast and easy from USB or CD/DVD (see Live CD or use my instructables)
///post your ideas///! COLLABORATE !
Specific PXE or GRUB boots and small USB drives can boot most any OS you choose
Image Notes
1 Boot a DSL linux image from USB
Image Notes
1 Samba or other tools allow access to NTFS, FAT and UNIX file systems (http://www.ntfs-linux.com/)
Trang 4step 2: Windows ISO Boot disc(s)
Free ISO Image Downloads:
These are the ISO boot disk images available from AllBootDisks
Download the ISO image you need, and if you need assistance creating a bootable CD from this image, visit the how-to page Everyone's seen Windows boot screens ugh think of ALL THE YEARS wasted watch DOS & Windows Boot!
ERCK
DOS4.01_bootdisk.iso
DOS5.0_bootdisk.iso
DOS6.0_bootdisk.iso
DOS6.21_bootdisk.iso
DOS6.22_bootdisk.iso
Win95a_bootdisk.iso
Win95b_bootdisk.iso
Win98SE_bootdisk.iso
Win98SEnoram_bootdisk.iso
Win98_bootdisk.iso
Win98noram_bootdisk.iso
WinMe_bootdisk.iso
WinMenoram_bootdisk.iso
ISO's are well documented already
step 3: Live CD distributions to choose from (list)
Live CD Distributions by # votes (alphabetical)
#Votes Name ISO Size (Mb Min Max) & Primary Function
0 3Anoppix 712 712 Desktop
0 ABC Linux 579 579 Desktop
0 Adios 700 700 Education
0 AdvanceCD 16 16 Gaming
0 AL-AMLUG Live CD 512 512 Desktop
0 AliXe 370 370 Desktop
0 AmaroK Live 289 289 Home Entertainment
0 Ankur 418 418 Desktop
0 Anonym.OS 575 575 Secure Desktop
0 ANTEMIUM 620 620 Desktop
0 Arabbix 550 550 Desktop
0 Archie 325 325 Desktop
0 Arudius 212 212 Security
0 Auditor security collection 538 538 Security
0 Augustux 700 700 Desktop
0 Aurox Live 698 698 Desktop
0 avast! BART CD 155 155 Rescue, Windows Antivirus
0 basilisk 650 650 Desktop
0 BDI-Live 138 138 CNC Metalworking
0 BEERnix 409 409 Desktop
0 BeleniX 637 637 Desktop
0 BerliOS MiniCD 182 182 Desktop
0 bioknoppix 681 681 Bioinformatics, Education
0 Blin Linux 36 160 Desktop
0 Bootable Cluster CD 188 188 Clustering
0 BOSS Live CD 646 646 Security
0 BrutalWareII 117 117 Security
0 Burnix 690 690 Clustering
0 ByzantineOS 43 43 Home Entertainment
0 Caster 545 545 Media Production
0 C� tix 717 717 Desktop
0 CDlinux 18 18 Rescue
0 CDMEDICPACSWEB 195 587 Medical
0 CHAOS 8 8 Clustering
0 CHRONOMIUM 68 68 Windows Antivirus
0 ClusterKnoppix 600 600 Clustering
0 Conectiva Linux Live CD 252 400 Desktop
0 Cool Linux CD 632 632 Desktop
0 Crash Recovery Kit for Linux 80 80 Rescue
0 Danix 683 683 Desktop
Trang 50 DeadCD 92 92 Desktop, Rescue
0 DemoLinux 650 650 Desktop
0 DeMuDi Live 575 575 Media Production
0 DevelopGo 695 695 Development
0 Devil-Linux 88 88 Firewall, Server
0 distccKNOPPIX 38 38 Clustering
0 Dizinha 154 154 Desktop
0 DNALinux 329 329 Bioinformatics
0 ECGL 706 706 Development
0 Echelon Linux 240 240 System Administration
0 eduKnoppix 700 700 Education
0 EduMorphix 643 643 Education
0 ELE 61 61 Secure Desktop
0 eLearnix 90 90 Education
0 elpicx 690 1382 Education
0 Emergency CD 174 174 Rescue
0 eMoviX 10 10 Home Entertainment
0 eZ publish LiveCD 487 487 Server
0 FCCU GNU/Linux Forensic Boot CD 519 563 Forensics
0 ffsearch-LiveCD 194 194 Server
0 FIRE 579 579 Forensics
0 fiubbix 670 670 Desktop, Education
0 Flash Linux 362 362 Desktop
0 FlashMob ISO 63 63 Clustering
0 Flonix 187 187 Desktop
0 floppyfw 2 2 Firewall
0 Formilux 38 160 Server
0 Freeduc 699 699 Desktop, Education, GIS
0 FuguIta 623 623 Desktop
0 GamesGo 698 698 Gaming
0 Gentoox 543 543 Desktop
0 GeoMorphix 672 672 GIS
0 Ging 164 164 Desktop
0 GIS-Knoppix 700 700 GIS
0 GISIX 635 635 GIS
0 GisMorphix 567 567 GIS
0 GNOME LiveCD 629 629 Desktop
0 gnome2live 430 430 Desktop
0 gNOX 242 242 Desktop
0 GNU/Linux Kinneret 623 623 Education
0 GParted LiveCD 52 52 System Administration
0 GPUL 534 534 Education
0 grml 49 696 OS Replacement, Rescue, Security
0 Guadalinex 592 700 Desktop
0 Hakin9 Live 625 625 Security
0 Hax Desktop 611 611 Desktop
0 Helix 701 701 Forensics
0 Hikarunix 182 182 Gaming
0 IndLinux Hindi 532 532 Desktop
0 jollix 506 506 Gaming, Home Entertainment
0 Julex 216 216 Desktop
0 JUX 695 695 Education
0 Kaboot 87 349 Desktop, Rescue, Science
0 Kalango 396 396 Desktop
0 KANOTIX CPX-MINI 230 230 Desktop, OS Replacement
0 Kazit 633 633 Desktop
0 KibZiLLa 288 288 Desktop
0 Klax 382 382 Desktop
0 Knoppel 648 648 Desktop
0 Knoppix 3.3 NY/NYLUG edition 702 702 Desktop
0 Knoppix en espa�±ol 651 651 Desktop
0 Knoppix for Kids 699 699 Desktop, Education
0 Knoppix Japanese Edition 681 681 Desktop
0 KNOPPIX-BV1AL 685 685 Desktop
0 KNOPPIX-EXTON 665 665 Desktop
0 Knoppix64 600 720 Desktop, Development
0 KnoppixQuake 130 130 Server
0 KnoSciences 661 661 Education
0 Komodo Linux 695 695 Desktop
0 Kororaa 695 695 Desktop, OS Replacement
0 KursLinux 696 696 Education
0 Kurumin 187 187 Desktop
0 LAMPPIX 157 207 Server
0 Legnoppix 380 380 Robotics
0 LFS boot-cd 240 240 OS Replacement, Rescue
0 LFS LiveCD 106 351 Desktop
0 LG3D LiveCD 606 606 Desktop
0 LinspireLive! 659 659 Desktop
0 Linux Live-CD Router 83 83 Firewall
0 Linux Magazine miniCD 185 185 Desktop, Rescue
0 Linux-EduCD 653 653 Education
0 Linuxcare Bootable Toolbox 47 47 Rescue
Trang 60 Lisp Resource Kit 612 612 Development, Education
0 LiveOIO 615 615 Medical
0 LiveZope 697 697 Development, Education
0 LNX-BBC 48 48 Desktop, Rescue
0 Local Area Security Linux 185 210 Desktop, Security
0 Lonix 149 149 Rescue
0 LUC3M 700 700 Desktop
0 Mediainlinux 691 694 Media Production
0 mGSTEP Live CD 88 88 Desktop
0 MiniKazit 180 180 Desktop, OS Replacement
0 MiniKnoppix 198 198 Rescue
0 MIOLUX 678 678 Desktop
0 Mono Live 702 702 Development
0 Monoppix 429 429 Development
0 Morphix-NLP 448 448 Science
0 MoviX 27 42 Home Entertainment
0 MoviX2 49 49 Home Entertainment
0 muLinux 68 68 Desktop
0 Myah OS 374 374 Desktop
0 NetMAX DeskTOP 697 697 Desktop, OS Replacement
0 Network Security Toolkit 262 262 Security
0 NeWBIE 641 641 Desktop
0 NIOde 550 550 Development
0 NordisKnoppix 699 699 Desktop
0 OnebaseGo 671 671 Desktop, OS Replacement
0 OpenGroupware Knoppix CD 546 546 Server
0 OpenVistA VivA 560 560 Medical
0 Operator 570 570 Security
0 Oralux 528 528 Desktop, Desktop
0 PaiPix 1720 1720 Science
0 Pardus Live CD 688 688 Desktop
0 Parsix 697 697 Desktop
0 Parted Magic 31 31 System Administration
0 PCG-C1VN Live CD 457 457 Desktop
0 Penguin Sleuth Bootable CD 689 689 Forensics
0 Pentoo 482 482 Security
0 Phrealon 34 34 System Administration
0 Pilot Linux 66 66 System Administration
0 PLAC 48 48 Forensics, Rescue
0 PLD Live CD 519 519 Desktop
0 PLD RescueCD 51 51 Rescue
0 PLoP Linux 40 40 Rescue
0 PlumpOS 51 51 Clustering
0 Pollix 695 695 Development
0 Public IP ZoneCD 271 271 Firewall
0 PXES 13 13 Thin Client
0 Pyro Live CD 622 622 Robotics
0 QiLinux 657 682 Desktop
0 Quantian 691 1961 GIS, Science
0 Repairlix 11 11 Rescue
0 RIP 9 25 Rescue
0 ROCK Linux 411 458 Desktop
0 Rxlinux 10 10 Server
0 Salvare 18 18 Rescue
0 Santa Fe Desktop Linux 614 614 Desktop
0 SchilliX 411 411 OS Replacement
0 SciLix 480 480 Desktop, Education, Scientific
0 SENTINIX 213 213 Security
0 Sentry Firewall CD 288 288 Firewall
0 Shabdix 680 680 Education
0 Shinux 99 155 Desktop
0 Skolelinux 662 662 Desktop, Education
0 SlackPen 322 322 Security
0 Slackware (Disc 2) 657 657 OS Replacement
0 slavix 624 624 Desktop
0 SLAX Frodo Edition 47 47 Diagnostics
0 Slix 693 693 Desktop
0 Slo-Tech Linux livecd 700 700 Desktop
0 SNAPPIX 553 553 Development
0 Sn�¸frix 695 695 Education
0 SoL-diag 35 546 Diagnostics, Rescue
0 Stanix Professional 660 660 Desktop
0 StarCD 530 530 GIS
0 StreamBOX-LiveCD 698 698 Media Production
0 StudioGo 692 692 Home Entertainment, Media Production
0 Sulix 700 700 Desktop
0 SuperRescue 701 701 Rescue
0 TeaM-TL 700 1320 Desktop
0 The Backpack Programmer's LiveCD 684 684 Development
0 TheOpenCD 596 596 Desktop
0 Thinstation 9 9 Thin Client
0 Tilix 705 705 Desktop
Trang 70 TiNA Knoppix 644 644 Science
0 tlf-morphix 404 404 Hobby
0 tomsrtbt 3 3 Rescue
0 Toothpix 717 717 Medical
0 TPM Security Server 294 294 Forensics, Security
0 Trinity Rescue Kit 50 50 Rescue
0 Trinux 19 19 Security
0 UHU-Linux Live CD 633 633 Desktop
0 uOS 261 261 OS Replacement
0 UserLinux 456 456 Desktop
0 VigyaanCD 647 647 Bioinformatics, Education
0 Virtual Linux 628 628 Desktop
0 WarLinux 53 53 Security
0 Wolvix 452 452 Desktop
0 WOMP! 13 30 Home Entertainment
0 X-Evian 633 633 Media Production
0 XAMPPonCD 88 88 Development
0 Xebian 269 269 Desktop
0 Xen Demo CD 720 720 Server
0 Xfld 650 650 Desktop
0 XNUXER 697 697 Desktop
0 XoL 700 700 Desktop
0 XORP Live CD 132 132 Firewall
0 Zaurus Development Version of DemoLinux 650 650 Development
1 aquamorph 382 382 Desktop
1 ATMission 530 530 Desktop, Server
1 cdlinux.pl 205 634 Desktop
1 Clusterix 275 275 Clustering
1 Freeduc-games 645 645 Gaming
1 Freepia 36 36 Home Entertainment
1 Frenzy 200 200 Rescue, Security
1 Gnoppix 659 659 Desktop
1 GNUstep live CD 420 420 Desktop
1 Kate OS LIVE 681 681 Desktop
1 knopILS 629 629 Desktop
1 Knoppix-MiB 650 650 Desktop, Secure Desktop
1 KnoppiXMAME 120 120 Gaming
1 KnoppMyth 469 469 Home Entertainment
1 Lin4Astro 595 595 Astronomy
1 LiveBSD 654 654 Desktop, OS Replacement
1 loonix-live 495 495 Desktop
1 Luit Linux 50 74 Desktop
1 Mandriva One 674 674 Desktop
1 MitraX 50 50 Desktop
1 Musix GNU+Linux 700 700 Media Production
1 NavynOs 384 384 Security
1 NetBoz 53 143 Firewall
1 Overclockix 655 700 Desktop, Diagnostics, Rescue
1 ParallelKnoppix 550 550 Clustering
1 Phaeronix 676 676 Desktop, OS Replacement
1 PHLAK 471 471 Security
1 Plan-B 658 658 Forensics, Rescue, Security
1 Sabayon 697 3477 Desktop
1 stresslinux 51 51 Diagnostics
1 STUX 255 650 Desktop
1 Symphony OS 568 568 Desktop, OS Replacement
1 T2 @Live 546 546 Desktop
1 Tao Live 675 675 Desktop
1 Whoppix 687 687 Security
1 Windows PE 0 0 Rescue
1 Zen Linux 307 564 Desktop, OS Replacement
2 austrumi 50 50 Desktop
2 BackTrack 625 625 Security
2 Baltix 703 703 Desktop
2 Benix Kanotix 189 189 Desktop
2 Berry Linux 425 425 Desktop
2 GeeXboX 5 5 Home Entertainment
2 Kurumin Games 708 708 Gaming
2 Morphix 203 648 Desktop, Gaming
2 redWall Firewall 148 154 Firewall
2 SLAX Popcorn Edition 104 104 Desktop
2 SLYNUX 730 730 Desktop, OS Replacement
2 VectorLinux 264 264 Desktop, OS Replacement
3 Feather Linux 63 63 Desktop
3 GoboLinux 634 634 Desktop
3 Kaella 700 700 Desktop, Education
3 KCPenTrix 401 401 Security
3 Knoppix STD 497 497 Security
3 LinuxDefender Live! 515 515 Rescue, Windows Antivirus
3 Mutagenix 99 549 Desktop, Diagnostics, OS Replacement, Rescue
3 SLAMPP 285 285 Server
4 FreeBSD LiveCD 413 413 OS Replacement, Rescue
Trang 84 Kubuntu 572 619 Desktop
4 m0n0wall 5 5 Firewall
5 BeatrIX Linux 167 167 Desktop
5 GoblinX Mini Edition 149 149 Desktop
5 INSERT 49 49 Rescue, Security
5 LLGP 695 695 Gaming
6 Suse Live-Eval 1446 1451 Desktop
6 SystemRescueCD 92 104 Rescue
7 Elive 200 700 Desktop
7 SLAX KillBill Edition 188 188 Desktop
8 Ultimate Boot CD 121 186 Diagnostics, Rescue
9 WHAX 574 574 Security
10 dyne:bolic 444 444 Clustering, Desktop, Media Production
15 FreeSBIE 596 596 Desktop, OS Replacement
15 Gentoo 50 1815 OS Replacement, Rescue
22 Puppy Linux 60 60 Desktop
23 Ubuntu 699 3553 Desktop, Os Replacement
34 MEPIS 693 693 Desktop, OS Replacement
38 Damn Small Linux 48 48 Desktop, OS Replacement
39 GoblinX 302 302 Desktop, OS Replacement
46 Knoppix 700 700 Desktop, OS Replacement
47 NimbleX 200 200 Desktop
83 PCLinuxOS 299 685 Desktop, OS Replacement
199 Kanotix 503 719 Desktop, OS Replacement
222 SLAX 41 202 Desktop, OS Replacement
Currently displaying 315 LiveCD/DVDs
Key:
Primary Functions:
Desktops: provides a working GUI desktop environment with a collection of desktop programs, such as browsers and text editors Many also include utilities for other purposes, such as home entertainment, but are only listed here because the additional functions are not their primary focus
OS Replacement: provides an option to transfer the cd to the hard drive, or to install an OS in a different form
Education: provides a collection of educational programs, or was created to be used in the educational field
Rescue: provides tools needed for data recovery
Clustering: provides tools for making clusters
Security: contains network security tools
Home Entertainment: geared towards playing video and audio
Gaming: video games!
Medical: contains medical programs
Diagnostics: contains utilities for testing hardware
Firewalls: distributions created to be used as firewalls
Forensics: distributions containing forensic tools
Servers: distributions used for various server functions
ISO Size:
The ISO min size and ISO max size refer to distributions which have different size images of the current release Sizes over 700MB may require overburning to be put onto a CD, or be a LiveDVD ISO Many LiveCDs can also be copied onto and booted from USB drives
Architectures
x86: AMD and Intel computers, could include optimizations from the 386 to the Pentium IV to the Athlon XP
x86-64: Computers with chips that use the AMD64 64-bit extensions, known in the Intel camp as EM64T These chips include the Athlon64, Opteron, Pentium 4 600 series, Pentium D, Core 2 Duo, and modern Xeons
PPC: PowerPC chips, including the Apple G3, G4, and G5 (in 32-bit mode), possibly other IBM Power chips
PPC64: PowerPC 64-bit chips, including the Apple G5, possibly other IBM Power chips
Eden: LiveCDs specifically made for the VIA Eden platform Because these are based on the x86 instruction set, x86 LiveCDs may work too
Xbox: Made for the XBox, may require software or hardware mods to run
IA-64: Itanium and Itanium2 platforms
Sparc64: SUN Sparc 64-bit platform
Alpha: Alpha platform, once made by DEC, then Compaq, and now being phased out by HP
Mips: Some SGI platforms
HPPA: Also known as PA-RISC, made by HP, also being phased out
http://www.livecdlist.com
Trang 9step 4: Browse any files NTFS FAT file systems (folders)
logon browse files from YOUR OS to their HDD (read only)?
recovered and copied
only the best DES or PGP files systems will prevent visual inspection
step 5: Protection ?
Only way is to triple encrypt (PGP or DES3) your raw data on HDD then upon discard perform a "clean" 23x rewrite "0" zeros and "1" ones then 23x write "1" ones then 23x "0" zeros
Then burn and chip (~1mm) the platters entire surface and submerge in nitric then sulfuric acids
DOD and NSA can read data off intact platters via electron scanning or Electron tunneling microscopes but not after the 23x triple re-writes and surface scour as the newer magnetic particles leave zero residual changes in the sub-medium
Most of the data can never be read
don't think so ?
most crooks and bad guys are not that well educated, that's how we catch you
Trang 10step 6: BIOS Backdoors
Bybassing BIOS Solutions:
1 BIOS passwords secure different levels of system access Lowest level is access control for power management functions, next for BIOS access (BIOS password) and highest level is for PC access (Administrator password)
2 BIOS password is stored in a non-erasable part of the CMOS ('BIOS memory') On desktop PC's this CMOS is buffered by an onboard battery Depending on your mainboard layout you'll see a seperate battery or won't see it as it will be integrated in a multifunction chip housing battery, real time clock (RTC) and other components (usually a small black brick on the mainboard)
Keeping that in mind different ways of removing the password are possible
Remove password with some kind of software
This works only if you have access to your PC and can run software (meaning no Administrator password is set)
CMOSpwd www.cgsecurity.org/index.html?cmospwd.html
Remove password by manually invalidating CMOS content
When CMOS RAM loses power, a bit is set to indicate this, which should cause the BIOS to detect that the CMOS RAM is invalid and will normally result in the loading of default values The same results can be obtained by using a simple DEBUG script to invalidate CMOS RAM This may be much more convenient than shorting pins on a chip in cases where it is possible to boot to a DOS prompt to run DEBUG.Here is a DEBUG script to invalidate CMOS RAM
This should work on all AT / ATX motherboards (some systems do not have CMOS RAM)
Boot from floppy with DOS or USb thumb drive
A:\>DEBUG
- o 70 2E
- o 71 FF
- q (Quits to DOS)
Remove password using common master passwords
Please be aware that most BIOS releases lock your PC completely after entering 3 wrong passwords !
American Megatrends BIOS
AMI, A.M.I, AMI_SW, aammii, AMI!SW, AMI.KEY, ami.key, AMI~, AMIAMI, AMIDECOD, AMIPSWD, amipswd, AMISETUP, BIOSPASS
Award BIOS
?award, awkward, award, award_?, award.sw, award sw, AWARD_SW, AWARD SW, admin, alfarome, aLLy, aPAf, BIOS, biosstar, biostar, CONTACT, condo, CONDO, g6PJ, h6BB, HELGA-S, HLT, j09F, j64, j262, j256, j322, lkw peter, lkwpeter, LKWPETER, PASSWORD, SER, setup, SKY_FOX, SWITCHES_SW, Sxyz, SZYX, t0ch20x, t0ch88, TTPTHA, TzqF, wodj, zbaaaca, 1322222, 256256
Phoenix
phoenix
SystemSoft PnP BIOS
system
manufacturer preset ones
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
Remove password on certain PC's and notebooks
IBM PC's and notebooks
Toshiba notebooks
HP notebooks
Remove password using Clear CMOS jumper on your mainboard
Please refer to your manual to locate this jumper Clearing CMOS will erase all passwords set but all your user defined settings like harddisk type, RAM timings etc, too You'll have to set these values again after clearing CMOS
Remove password by clearing CMOS due to disconnected power
CMOS content is buffered by an onboard battery If you disconnect this power supply your CMOS clears automatically as the content can't be refreshed due to the missing power This works easily if you see the onboard battery Remove the battery for at least 5 minutes an insert it again in it's socket
Remove password by clearing CMOS within RTC chip
Depending on the RTC chip used on your mainboard you can reset CMOS content by connecting two pins on the RTC chip A paperclip bent into a U shape is a good tool for this For all the following activities your PC has to be powered off
Chips & Technologies P82C206
This is usually a square PLCC chip, sometimes soldered onto the motherboard, sometimes in a socket CMOS RAM on this chip is cleared by shorting together pins 12 (GND) and 32 (5.0V) or pins 74 (GND) and 75 (5.0V) for a few seconds
Pins 12 and 32 are the first and last pins on the bottom edge of the chip, pins 74 and 75 are the 2 corner pins on the upper left corner