Helping people with computers... one answer at a time.

A BIOS password provides a surprising amount of security on a computer. So much so that if the password is lost, the chances for recovery are slim.

How do I remove BIOS password? I can't boot CDs; how can I fix this without knowing the BIOS password?

You probably can't.

BIOS passwords - which you enter before even booting to allow the process to proceed - turn out to be fairly tough items to crack. That's (mostly) great news if you're trying to protect your computer.

Unfortunately, it's pretty bad news if you don't know the password and need to get in.

Let's review the options...

BIOS Passwords

Example BIOS chip on a motherboard
Example BIOS chip on a motherboard

The BIOS, or Basic Input Output System, is the software that's actually stored in a memory chip on your computer's motherboard. It performs many functions, but the one that we're most familiar with perhaps is that it's the software the gets control of your machine from the moment you turn it on or when you reboot it. It's then responsible for locating the boot device - hard disk, CD, USB or floppy - and loading the software that takes over the next stage of the boot process from it.

Many, if not most, BIOS's can now be programmed to require a password before allowing you to do anything.

By anything, of course, I mean anything; if you don't know the BIOS password, you can't boot, you can't alter any BIOS settings, and, of course, you can't reset the BIOS password.

As I said, it's fairly strong security, if that's what you're looking for. Given how often people forget passwords, it's almost too strong; if you forget it, you are very likely completely out of luck.

I know of four scenarios if you forget your BIOS password.

Changing the Password Normally

Almost every brand of BIOS is different, so I can't give you step-by-step instructions. There's at least one bit of information, though, that is common:

In order to change or remove the BIOS password, you need to know the BIOS password.

It makes sense, of course, from a security perspective, but when you're faced with a machine whose BIOS password is unknown, it puts you in a very difficult position.

Potentially, an unsolvable one.

Hardware Reset

Very few computer manufacturers provide consumers with the ability to reset the BIOS password by setting a jumper on the motherboard. The only way to know if this will work for your computer is to contact the manufacturer of the computer or its motherboard.

The reason that this is infrequent is that the jumper defeats the purpose of the BIOS password in the first place. For example, a thief who has successful stolen your machine can contact the manufacturer, find out how to reset the password, and get right in.

Factory Reset

I have heard of some scenarios where the computer manufacturer will, possibly for a fee, reset the BIOS password for you. Typically, that means shipping your computer back to the manufacturer where they have access to resources that you and I do not, and they perform whatever magic is appropriate for their machine to unlock it.

Naturally, this is a good theft deterrent because a thief isn't likely to bother sending a machine off to a manufacturer where it can likely be traced back to him.

I do believe that this is also a very uncommon practice, but I could be wrong.

Motherboard Replacement

There may simply not be a way to reset the password, and therefore, no way to unlock the BIOS.

One alternative in this scenario is then to replace the motherboard, BIOS and all. With a new motherboard with an un-passworded BIOS, you'll have access to everything you need.

Computer Replacement

Sometimes, the bottom line is simply that a machine with an unknown BIOS passwords is, for all practical purposes, unsalvageable. It's a shame, but it's an unfortunate reality. If the hard drive is not itself password protected (the subject of a future article), getting a completely new computer and either installing the old hard drive, or attaching it as an external drive, is perhaps the most expeditious solution.

BIOS passwords actually provide a surprising level of security, but only to a point, as an unprotected hard drive could be placed in a different machine without a BIOS password.

Regaining control of a computer whose BIOS password is unknown is iffy at best and frequently a lost cause.

Bottom line: don't forget the BIOS password.

Article C4777 - March 26, 2011 « »

Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

Not what you needed?

Houssam Mousa
March 26, 2011 8:58 AM

We used in the past to take off CMOS battery, I think this still work, does not it?

If it does that's not a very secure BIOS password. I believe that most modern motherboards do not reset the BIOS password when the CMOS battery is removed.

March 26, 2011 9:11 PM

I have never seen a motherboard without a bios reset jumper... New model motherboards require you to source a jumper...

Those jumpers don't always reset the BIOS password; sometimes just the BIOS version or other settings, while the password remains in place. As I said, there is no consistancy.

March 29, 2011 8:40 AM

Why not just upgrade or if not available downgrade to an older Bios version by downloading what you need from the manufacturer and flash it? Then repeat the process with the current/upgrade.

Some manufacturers will PW protect the Bios to prevent overclocking and associated 'cockpit' problems during the Warranty period.

I believe the jumper is to allow one to revert back to the factory firmware, should a problem be encountered when flashing, rather than rending the motherboard inoperable.

Built in safety net, since the Eeprom is large enough to hold two versions so let's say the original BIOS lives in the bottom half, hence the jumper.

John Moore
March 29, 2011 8:51 AM

I have a several years old Vaio VGC-RA820G desktop which has never let me in to the BIOS? It never asks for a password and I have tried every imaginable combination of BIOS entry codes with no luck. I asked about this a year ago and got no answer. How is this possible and HOW DO I GET AROUND IT! Thanks. I'll buy you another coffee if you can give me any hints! I want to install a larger hard drive, but it just doesn't get recognized without BIOS intervention.

March 29, 2011 9:00 AM

I have seen cases where an energy surge reset a Bios... perhaps use this somehow as a last resort... trouble is how to recreate an energy surge without loosing the patient!

Jeff Woolston
March 29, 2011 9:26 AM

I had a sister who had a friend giver her an older Compaq computer that they said was "broken". She knew I worked on computers so she asked me to "take a look at it".

Bottom line... the problem was that it had an unknown Bios password. I removed the internal battery, rebooted into the bios and reset the Bios password to nul (blank), and that solved the problem. It does still ask for the password on boot up, but all you have to do is press enter since there is not one assigned. This may not work everytime, but it did this time.

I hope you find this useful information.

March 29, 2011 9:29 AM

If you Google default BIOS passwords, there are sites that will give the most common manufacturer default passwords. It's worth a try.

Jeff Woolston
March 29, 2011 9:31 AM

Oh, by the way, I did replace the battery after the initial reboot and, yes it still worked fine. Sorry I left that important step out.

March 29, 2011 9:37 AM

Just take out the cr2032 battery for 10 minutes and then reset everything to the defaults. The hard drive should be auto detected. It has been years since I bought a computer, so this information may have changed to flash memory, in which case you are out of luck.

John S.
March 29, 2011 10:00 AM

Hello, A few years back i had a couple different customers bring me laptops with bios password protection and no password. One was an HP, the other a dell. I had also puchased a Dell laptop from Ebay with bios password problems for dirt cheap. Needless to say, the HP i simply called customer support & with the customers name and address, was able to reset the password since they had registered the computer after purchase. HP support gave me a reset password & this allowed me access to the bios where i did away with the need for a password so this would not happen again. The Dells', i would up buying a password reset disk "hack" from, you guessed it, Ebay. There's a guy on Ebay, who if you give him the bios number that can be found on the page that asks for the bios password, all he needs is the last few numbers, he sends you a disk that generates a new password on a working computer. Like i said, it's been a few years and i don't recall exactly how i did it, but it did work. You can also try Service Manuals: if you have a Dell.
Good Luck! don't give up my friend. All is not lost. Chalk it up to a learning experiance!

Sandy Coulter
March 29, 2011 10:37 AM

I haven't had to do it lately but removing the cmos battery always worked for me in the past.

Jeff Colmenter
March 29, 2011 12:00 PM

As Steven mentioned above, take out the motherboard battery (which holds your CMOS settings), being a CR2032 usually for a while and reinsert it. It can reset HDD and CD/CDR/DVD/DVDR DL and Blueray drives where I had to press enter on the auto detect to see that it took the drives, then save and exit.

March 29, 2011 12:15 PM

Yeah, remove the battery and sip your coffee.
Reinstert the battery and you're brand new.
Everything is reset.
Try it.

March 29, 2011 12:36 PM

just remove cmos cell and put it back it will work

On some, but not all, motherboards.

Sandipan Adhikary
March 29, 2011 2:03 PM

Removing the battery (the button cell) on the motherboard, flushes the BIOS and resets the password. The easiest way, so far known to me.

Which does not work on all motherboards.

March 29, 2011 6:51 PM

remove cams battery and start off ur pc and inset the battery enjoy

This doesn't work on all motherboards.

Onsite Pc
March 29, 2011 10:34 PM

Never set one in the first place! A bios password is a no no. Especially when we tech's need to boot other than hard drive, and yes, the owner does not know anything about a bios password! ugh! take your mobo out and burn it. It is even more of a disaster on a laptop and can make the whole machine a financial dud.

March 30, 2011 1:37 AM

Re-install your motherboard bios its easy, take a look at the motherboard name and then got to the motherboard website download the bios prog for your board and re install it ,full details how to do it on the site.

Depending on the motherboard this may not reset a BIOS password.

March 30, 2011 6:59 AM

Reading the comments on removing / replacing the battery...

I've seen several motherboards where there IS no battery... I'm assuming the BIOS is some sort of power-independant memory or there are some (possibly disguised) capacitors that charge while the Pc is in use.

Glenn P.
April 2, 2011 8:21 AM

Unfortunately, not  setting a BIOS password isn't always an option.

In our household there are two of us: myself, a computer-literate person, and my mother, who wouldn't know a BIOS from a Bitmap or a User from a USB.

For her sake, I've implemented a BIOS password, because God help us both if she happens to hit the Wrong Key while the computer is booting and finds herself at the BIOS screen! Being scared to death (which she definitely would be) and frantically trying to "get out of it", there is a better-than-middling chance she would end up randomly Changing Something by mistake... and God Only Knows what that would be!

So I've set a BIOS password, an evil I must live with for our mutual protection. It's just my Windows logon password, so there's no chance of my forgetting it; but she has no idea what it is, so we're both safe.

April 6, 2011 8:37 PM

Thru my travels. Some motherboards had a reset bios button, also some had a jumper that you take off, and most had nothing. You real need the motherboard manual.

David from Brevard
April 10, 2011 6:04 AM

Please comment on this article:
This seems to be fairly complete and isn't as pessimistic as you appea to be. There seems to be something that you, or they missed, or more likely, that I missed.

In a way they almost make my point. There are dozens of different instructions to try, approaches to take, all of which depend on the specific computer and motherboard and BIOS. I'm sure that for those they list that it works great. However they're providing information for those that presumably work and simply don't mention those for which there's no solution. Absolutely their information is worth a try. I'm also very concerned by the incredible number of comments on the article from people who are still looking for BIOS unlocks even with all the information that the article provides.

Alexander Silva
July 21, 2011 4:02 AM

I liked your article. I think for most computer users it is a good message to send to remember your passwords. I think that you could have done more as far as educating people about the options for when you can't remember. I am surprised that you didn't talk about the most common solutions for removing a BIOS password. I think you could really benefit by making a update to this article or a new article about what to do when you can't remember the bios password. I know that it is a commonly searched term and a lot of people need help with this.

I own a own computer and laptop repair / tech support business so I actually run into this problem all the time. I can honestly say 100% of the time I can remove the BIOS password with virtually no effort. The new anti-theft models take more time to remove than most but usually I can have the BIOS password removed in less than 10 minutes. Typically 5 minutes. I thought you could benefit from this information and feel free to use this information for this article or a new one. These are my typical solutions.

1) master password AKA backdoor password- typically only 2005 and earlier models but certain manufacturers used them longer.

2) cmos battery removal works on almost all laptops and pc's except for the newest ones with anti-theft by hard hard password cache. (how to remove this one is below)

3) short the jumpers method -

4) EEPROM decoding method - you need an EEPROM reader.

5) loopback dongle method - For older computers with a 25 pin port. While dongle is in the password is disabled when you remove it the password goes back to normal. For a locked system this allows you to access the system and boot menu to boot from cd so you can flash the bios with a new version and erase the password. Here is a link to the article about how to build one. The compatible models list is missing a ton of models because he only tested it one those models. It works on a lot more models than listed.

6) IC Extract method - remove bios chip and put a new one in.

7) Flash the bios with a new version - works on every pc and laptop except for the password on a hard drive cache.

8) Hard Drive BIOS password cache - use a linux live cd to edit the partitions and delete the password cache partition. You need to securely delete the partition I suggest a 7 wipe dod standard wipe there is a free program for this called dariks boot and nuke it has secure hard drive wiping.

Here is a link to a site that has all the master passwords for almost every motherboard listed. They also list a million other bios related removal tools.

Comments on this entry are closed.

If you have a question, start by using the search box up at the top of the page - there's a very good chance that your question has already been answered on Ask Leo!.

If you don't find your answer, head out to to ask your question.