Forgot your Android phone lock screen PIN code for your Google account and have a locked phone? And that is necessaryunlock your android phoneuse your lock screen? Don't worry, you're not the only one who forgets his PIN. I'll show you how to unlock the lock screen on Android phones.
Passcode pins serve as that of your Android phone and to protect your Google account from unauthorized use on your lock screen. Although some have new security features on your Android device like fingerprint unlock for Android lock screen to unlock your Android device for your Google account, still some people prefer to use passcode PIN and passcodes on their Google account as their lock screen. It can be stressful and time consuming if you forget your Android device or mobile device password and even worse, are completely locked out of your lock screen. And it may be difficult to unlock your Android at first.
Be that as it may, it is frustrating to lose access to your Android phone or your Google account and know how to unlock your Android phone. You can always go to a store to unlock your Android phone, but it will only cost you to unlock Android.
But do not worry! I know a few methods to unlock your Android phone. You can download software such asDownload Tenorshare 4ukey for Androidto help you unlock your phone in just a few steps. Apart from this, there are several methods available.
In addition to unlocking the Android phone, some of thebest ad blockers for androidcan even help you get rid of the annoying lock screen ads. So if you are facing a similar issue, I highly recommend giving these ad blockers a shot.
So, before you go for a hard reset and lose all your data to regain control of your Android lock screen, try these methods first. With these tips, you can access your Android phone in minutes. Let's start!
Related:The best lock screen apps for Android
SponsoredUnlock your Android phone without password using Droidkit
Most Android phones have different types of lock functions. But at some point people forget their passwords or lock patterns. When you use your phone's facial or fingerprint recognition feature, there's a chance that it won't work properly.
When this happens, you can try iMobie'sDroidkitto unlock your phone regardless of the type of screen lock you have used. This tool is usable with more than 20,000 Android smartphone and tablet models.
You just need a working Mac or Windows PC on which you can download this tool and follow the instructions to unlock your phone in minutes. And if you're concerned about rooting, Droidkit doesn't require you to root your device.
10 Easy Methods to Unlock Android Phone
Try these easy methods to unlock an Android phone.
- Use Google account
- Use Android Debug Bridge
- Unlock Samsung with PC
- Use dr.fone
- Boot into safe mode
- UI crash lock screen
- Use Android Device Manager
- Use fingerprint
- Use face unlock
BONUS METHOD:Using PassFab Android Unlocker
1. Unlock your Android phone with your Google account for your locked phone
What you will need:
- Your Android phone with your Google account
- Access your synced Google account on your Android phone
This method uses your Google Recovery account to unlock your Android lock screen on your Android phone from your Google account Android lock screen. One of the benefits of Google account integration is that Google accounts are intertwined with most of your other Android devices, giving you the ability to access your Android phone from your Google account on your Android phone. device and unlock it.
- If you don't have access to your Google account, you can skip to method 3, which uses ABD commands to open yourandroid phone.
- This option is only available on devices running Android 4.4 or lower.
Step 1: Tap "Forgot Password" on your Google account
To unlock your Android phone, on your Android lock screen, tap "Forgot Password" in your Google account to access the Account Unlock menu on your locked phone.
Step 2: Sign in to your Google account
Google accounts are essential and so we should always have access to them so that we can fully utilize their capacity. This can help you unlock your Android phone.
Enter your Google account information on your Google account and tap "To registeron your Android device. From there you can reset your Google account pattern or passcode on your Android phone for your Google account to unlock your Android phone.
You will be prompted to reset your Google account passcode to unlock your Android phone with your Android phone right after you sign in. Make sure you set one up for your Google account that you can easily remember on your Android phone.
If your Google account information isn't working on your phone, you may need to restore it using your PC. Visit Google's account recovery page and follow the steps above to regain access to your Google account.
2. Unlock Android Phone with Android Debug Bridge (ADB)
If you haven't tried ADB before, now is a good time to unlock your Android phone. Using a series of ADB commands you can unlock your Android phone to your Google account, provided you haveUSB debugging enabledon your Android phone. If you don't, this method won't work for your Android phone to unlock your Android phone.
There are some steps you should go through first to fix your Google account if this is your first time using ADB:
- If you don't have any Android SDK tools installed, or if you've set your device to accept ADB commands but don't quite understand how to use it, check out our article onADB and how to use it.
You must confirm that you have set up SDK and ADB correctly. To do this, open yourmap platform-tools,and then open a "command prompt" in it.If you've done this before, go to step 3.
- You can open the command prompt in a folder withShift + right clickand then selectopen the command window here. (Some PCs may show "PowerShell")
Now there are two commands you need to enter to confirm your ADB configuration.
- ADB version- this will reveal the version number of your ADB software.
- ADB devices- Before this, make sure to connect your Android phone to the PC. Once your device is connected, your phone's serial number should appear in the command prompt window. If you can't find the serial number, try reconnecting your Android phone.
You must enableUSB debuggingfor this method to work, but luckily there is a way around this. If you boot your Android phone into recovery mode, you can perform these steps as usual, without having to enable USB debugging. However, your Android phone partition needs to be mounted:
- Go toConfirmations and storagein your recovery on your Android device.
After doing this, you can proceed as if USB debugging is enabled.
For non-rooted devices
there are two steps:
Step 1: Open a command prompt
This process is a bit confusing so make sure you follow the steps on your Android phone carefully to unlock your Android phone. With your Android phone connected to your PC - and the cmd open -enter the following commands in order:
- adb scale
- sqlite3 settings.db
- update system set value = 0 where name = 'lock_pattern_autoblock';
- update system set value = 0 where name = 'lockscreen.lockedoutpermanently';
Step 2: Reboot your device
After you complete this, reboot your Android device. If this doesn't reset your Android lock screen, continue to the next step.
With your Android phone still connected to your PC and the command prompt opens, enter:
- abdshell rm/data/system/gesture.key
Once that's done, reboot your phone.
With the cmd open in the right place and your phone connected to the PC,enter the following commands:
- adb scale
That wasn't that hard, was it? If this method didn't work for you, there's still hope! I have another method where you don't have to erase all your data. Let's check that out and see if it works!
3. How to unlock registered Samsung device
If you have a registered Samsung smartphone, it's your lucky day. The company offers a way to unlock registered Samsung smartphones with your Google account.
What you will need:
- Your Android device
- One registeredSamsung-account
- A PC
Open theSamsung-websiteon your PC and log in with your account details.
Select your Android device from the task bar on the left to unlock your Android phone.
Find the optionUnlock my screenon the sidebar.tap it,and unlock your phone's lock screen.
4. Unlock Android phone with dr.fone
The next way to unlock your Android phone is an app calleddr.fone - Unlock (Android). This Android Lock Screen Removal tool can unlock Android phone lock screens with pattern, PIN, password and fingerprint.
Remark:You need a computer to use this method to unlock your Android phone.
Step 1: Download the app
Dr. fone from the developer's website to unlock your Android phone.
Step 2: Open the app
Launch the app on your computer and clickUnlock.
Step 3: Connect your device to your PC
Now connect your Android phone to your PC with a USB cable and then clickBegin.
Step 4: Check your phone's information
If your phone is successfully connected, information about your phone should appear on the screen. If it is correct, pressFollowing.
Step 5: Begin to remove the password
Boot your Android phone into download mode and then the recovery package will be downloaded. After that, password removal starts and a confirmation message appears on the screen.
5. Unlock the Android phone by booting into "Safe Mode"
It is possible to unlock Android phones through safe mode. Keep in mind that this method only works for your Android device and phones that have athird-party appas the lock screen to unlock your android phone. This method works by temporarily disabling the third party app and giving you a way to reset it to unlock your Android phone.
Step 1: Boot into Safe Mode
For most phones and your Android device, you can do this by opening the power menu and long-pressing "Switch off.” A notification will appear asking if you want to reboot in safe mode, press OK.
Step 2: Clear your lock screen app data.
Clear or uninstall data from your lock screen app and reboot your phone to exit safe mode. When you do this, you unlock your phone or Android device.
6. Crash the lock screen UI to unlock Android phone (Android 5 only)
Before trying this one to unlock your Android phone, keep in mind that its method only works for devices runningAndroid 5.0-5.11, so if your phone doesn't have this version, move to the next process.
This method of bypassing a locked screen is just a stopgap solution for the phones in this category.
Step 1: Tap the "Emergency" button.
Enter 10 asterisks (*) through the dialer.
Step 2: Copy the stars
Copy the asterisks and paste them on the dialer until the "Placingoption no longer appears.
Step 3: Tap "Camera"
Return to the lock screen and tap the camera shortcut icon.
Step 4: Tap "Settings"
Hit the settings option on your Android device after pulling down the notification bar. Now you have the option to enter the password and you have to repeat the same here to unlock your Android phone. Stick until the lock screen crashes.
7. Unlock Android Phone with Android Device Manager (ADM)
Using this methodFind my device from Googleto perform a remote factory reset. It not only removes your Android phone's password or pattern and your lock screen password, but also all the data on it.
Remark:This only works if you enable Find My Device on the phone, and again, it willdelete all dataon your phone. If this is not what you want, I highly recommend that you try one of the above methods on your Android device.
Step 1: Find your device
On your computer, go to the "Find my device” website.
Step 2: Select "Erase my device"
You will see this on the left side of your screen. Once you confirm the Erase feature, your phone will boot into recovery and begin doing a factory reset. Once you approve this action,it is impossible to stopor cancel on your Android device. Even if you shut down your Android phone, the reboot will resume on startup.
8. Unlock Android Phone with "Factory Reset"
What you will need:
- Your Android device
- A USB cable
- A PC
If you don't have the "Find my deviceoption enabled on our phone, you can do it the old fashioned way on your Android device.
If you're still stuck behind a lock screen, unfortunately the amount of personal data you can store is limited along with your Google account. However, here's what you can do to save what you can:
- Connect your device to your computer
- Find your phone and open the root folder with your PC
- Copy any folders you want to keep and save the files
- Depending on your Android device, the factory reset steps may be slightly different, but the results will be the same on your Android device.Most devices allow you to perform a hard reset by entering recovery mode.
- Use this methodwill erase all data on your device.I highly recommend backing up your content if you use it as your last resort.
Step 1: Open the boot menu
Turn on the Android device and run itstartup menu.If you can't access it with the above method, do a quick search for your Android phone model and how to access safe mode.
Step 2: Access Safe Mode
In safe mode. Use the volume keys to navigate up and down, press the power key to confirm your selection on your Android device.
Step 3: Reset your device
Find theErase data/restore factory settingschoice.
After confirming the option, your Android phone will begin the process - this may take a few minutes. When completed, your Android device will reboot without your passcode,but also without your data.This process unlocks Android phones, but also deletes all information; unless you have oneback-upof your files, do not perform a factory reset on your device on your Android device.
9. Unlock Android with a fingerprint
This method allows you to unlock the Android phone without changing the PIN or pattern. The Android phone can be unlocked in a second by using this method and it is the simplest of all the methods mentioned above. For this method to work, you must have already added a fingerprint to your Android phone. This method only works for Android phones with a fingerprint sensor.
Follow these steps to unlock Android with a fingerprint.
Step 1: Add fingerprint to your phone
To add a fingerprint to your phone, go to Settings > Security > Fingerprint > Add Fingerprint. Then follow the onscreen instructions to add your fingerprint to your Android phone.
Step 2: Unlock Android phone with fingerprint
Once the fingerprint is added, you are all set to unlock your Android phone with your fingerprint. Just place the added fingerprint on the fingerprint sensor and your phone will be unlocked.
10. Unlock Android phone with face unlock
This is one of the most emerging technologies in the smartphone world. All new phones nowadays are equipped with a Face unlock function. With this method, you can unlock your Android phone without any hassle, just look at the front camera of your Android phone. Keep in mind that face unlock is not as secure as fingerprint unlock as anyone who resembles your appearance can unlock your phone. also it can unlock the phone while you look at it if you don't intend to.
Face unlock only works if it's already set up on your phone, so before you forget your PIN or pattern, set it up on your phone. Follow these steps to unlock your Android phone with face unlock.
Step 1: Set up face unlock on your phone
To set up face unlock on your phone, go to Settings > Security > Face Unlock > Set up face unlock.
Follow the on-screen instructions to add the Face ID.
Step 2: Unlock Android with face unlock
That's it, next time you want to unlock your Android phone, just look at the front camera, it's that simple.
Bonus Method: Using PassFab Android Unlocker
PassFab Android Unlockeris an easy-to-use tool that can unlock your Android's PIN, pattern or password in case you forgot them.
Here's a brief overview of how to use PassFab.
- Download the software on a computer.
- Connect your Android device to the computer with a USB cable.
- Choose the "Remove screen lock" option. You will get the options "Remove screen lock" and "Remove screen lock without data loss". The first option is available for almost all Android phones while the second option only supports previous Samsung smartphone versions like Note 3, Note 4 and S5. Choose the function suitable for your device.
- Then you just need to click "Start" and then follow the instructions and read the messages carefully to unlock your Android phone. It just takes a while.
You can view more information and a detailed step-by-step planguide on how to use PassFab Android Unlocker here.
Frequently Asked Questions
Can someone unlock my stolen phone?
Yes, doing a factory reset will wipe everything on your phone to make it look like it was just taken out of the box. So, the only good news is that in any case, there is no way for them to get your data onto your Android device.
Does a factory reset unlock Android phones?
A factory reset will delete all data you have on your phone including settings. So technically, after a factory reset, it will be like opening your Android phone for the first time.
How to unlock LG phone without password?
Try to unlock your LG phone several times. When you've reached the limit, tap Forgot pattern. Then enter your Google account username and password. Your phone will be unlocked. Go to Settings and reset the pattern.
What is the best Android password cracking software?
dr. fone is by far the best lock removal tool out there. It helps you remove all types of locks, namely pattern, pin, fingerprint, face ID. The tool is quite easy to use, even for non-tech savvy people. Tenorshare 4ukey for Android is another good password bypass tool for Android. Whether you forgot your password or made too many wrong attempts, this software will help you unlock Android devices in minutes.
Does a factory reset remove the root?
It depends. If your factory reset only deletes user data and cache partitions, it will not wipe your phone.
On the other hand, if the factory reset involves uninstalling and reinstalling the system, your phone will be undone.
How to unlock Samsung Galaxy S8 forgot password?
Try these methods to unlock your Samsung Galaxy S8 if you forgot your password. Another way to unlock your Samsung Galaxy S8 phone if you forgot the password is Samsung File my mobile. If you previously configured Samsung Find my mobile on your phone and connected to the Internet, this method will work. the last option is to factory reset your phone, losing all your data if your Google or Samsung account is not backed up.
How to unlock a Samsung tablet if you forgot the password without losing data?
To unlock a Samsung tablet when you forgot the password without losing data, you must have already configured Samsung Find My Mobile on your tablet. to do this, go to Settings > Biometrics and security > Find my mobile and turn on the switch. Then enter your Samsung account information if you already have one or create a new account. If you have not yet configured Samsung Find My Mobile on your Samsung tablet, you will not be able to unlock it without losing the data and it will be reset to factory settings.
Passwords protect our device from unauthorized users, but sometimes we get accidentally locked out on our lock screen on your Android device. Forgetting your password can be quite annoying, especially if you just changed it.
Hopefully, I was able to help you regain access to your locked device without factory resetting your Android device. However, sometimes you have no other option to unlock your Android phone.
If you reset your passcode, make a note of your last change and put it in your wallet or email yourself, that way you have a better chance of getting back into your phone with your password for the lock screen.
If I missed a way to unlock an Android phone, or if you have any questions, let me know in the comments section below!
What is the master password to unlock any phone? ›
There is no master pin for an Android phone. Everything from 0000 1234 or whatever you can think of.Can you unlock Android without code? ›
You can unlock your Android phone even if you've forgotten the passcode, but you'll usually need to factory reset the phone. You can unlock most Android phones by performing a factory recovery or using the Find My Device website.What three methods can be used to unlock a smartphone? ›
- Fingerprint sensor. Life became a lot easier with the coming of fingerprint sensor technology in smartphones. ...
- Voice unlock. ...
- Unlock with Bluetooth device. ...
- Iris scanner. ...
- Location-based unlocking.
The most recommended phone unlocking software is called DroidKit – Android Phone Toolkit. It's capable of removing the screen lock on your Android phone without entering the password. No matter you are using PIN, password, pattern, fingerprint ID, or face recognition, you can unlock your phone with DroidKit.What is * * 4636 * * Android secret codes? ›
*#*#4636#*#* Displays information about the phone, battery, and various network statistics.How do I unlock my Android phone without factory reset? ›
- Sign into your Google account and go to the Google Locate My Device page.
- Choose the Android device that you wish to unlock.
- Enter a new password and click the “Lock” button.
- To confirm, click “Lock” once again.
The only way a phone becomes permanently locked is if an invalid unlock code has been entered too many times.Is there an app to unlock phone without password? ›
DroidKit – Unlock Android Phone without Password
Just free download DroidKit to unlock any Android screen lock, like password, PIN, pattern, etc. Supports all Android phones & tablets, including 20,000+ models like Samsung, Vivo, Motorola, etc.
What Is SIM Network Unlock PIN? SIM Network Unlock Pin (NUP) is a code used to unlock an Android phone or iPhone from its original carrier so that it may be used on other carriers. This code is typically 8 or 16 digits long and is used to unlock a smartphone.What is the most common pattern to unlock a phone? ›
77% of Android device users start their patter on one of the corner dots. 44% of Android device users start their pattern from the top-left corner of the first dot. Most Android lock screen pattern users use less than 5 dots and a significant percentage of them use only 4 dots.
What is unlock network code? ›
The Network Unlock Code (NUC), sometimes called a Network Unlock PIN (NUP) or Network Control Key (NCK), allows you to unlock a mobile phone from its original network. If you've not received a NUC you can request one.What program is used to unlock phones? ›
Android Device Manager (also named "Find My Device") is a security system from Google Play Protect. This software allows you to bypass Android lock screen without reset data.What is the Android device unlock app? ›
Device Unlock is an Android app that allows you to request and apply a mobile device unlock directly from the device.What does * * 7780 * * do? ›
2. *#*#7780#*#* (Run a Factory Reset) If you don't want to run a hard reset, this is the next best thing. Similar to a factory reset, this code will simply delete all application data from your device, as well as any applications.What does ## 002 do to your phone? ›
##002# - If your voice call or data call, or SMS call has been forwarded, dialling this USSD code will erase them. *#21# - By dialling this USSD code, you would get to know if your calls have been diverted somewhere else or not.What is *# 31 code? ›
Hide Caller ID: *31#
The caller might have hidden the ID intentionally or sometimes it can be accidental. If you want to hide the caller ID dial *31# and press call button.
Yes, a universal unlock pattern for Android exists. This built-in feature is commonplace with all Android devices and OS versions. This feature is quite interesting because it shows how thoughtful Google can be, knowing that passwords/PINs/patterns can be lost at any time.How do I reset my lock screen password if I forgot it? ›
Reset a device password
Sign in using your administrator account (does not end in @gmail.com). Mobile devices. Select the device and click Reset Device Password. Enter and then confirm the new password.
When a handset is locked it means it will only work with the provider that you bought it from. If your phone is locked it won't automatically become unlocked when your contract expires with your provider. You'll have to specifically ask your carrier to unlock it.What to do when Android is locked? ›
- After you've tried to unlock your phone multiple times, you'll see "Forgot pattern." Tap Forgot pattern.
- Enter the Google Account username and password you previously added to your phone.
- Reset your screen lock. Learn how to set a screen lock.
What app removes phone password? ›
It can remove pin lock, pattern, password, fingerprint, face ID, and Google account verification. You can then use a different Google account and access your phone to its full potential. Similar to Dr. Fone, this tool also allows you to remove lock from a Samsung phone without any data loss.
The default SIM unlock code for T-Mobile and Sprint is 1234, while the default unlock code for Verizon and AT&T is 1111'. If you don't know the PIN, try the default code first. After you enter the code incorrectly too many times (the number varies), you'll be prompted to enter the PUK.What is the default SIM unlock code? ›
Default SIM Pin Codes of Popular Mobile Carriers
1. Default SIM Pin code of Sprint and T-Mobile is 1234. 2. Default SIM Pin code of AT&T and Verizon is 1111.
While trying to use SSH, you may get a response indicating permission is denied. Or if you get an error with a code of 255, it means there's a problem with your SSH connection.What are all possible patterns for the Android lock? ›
- 4 dots: 1,624 combinations.
- up to 5 dots: 8,776 combinations.
- up to 6 dots: 34,792 combinations.
- up to 7 dots: 107,704 combinations.
- up to 8 dots: 248,408 combinations.
- up to 9 dots: 389,112 combinations.
These two attacks to the lock mechanism are commonly referred to as heuristic attack and smudge attack 1 2 3. Now the question is how many unlocking patterns are there, really? The answer is 389,112.How to bypass Samsung pattern lock? ›
- After drawing a wrong pattern 5 times on your Samsung phone > Tap Forgot Pattern at the bottom of the lock screen.
- Type in your Email Id and password to unlock the device. Then tap on the Sign-in tab.
- You will be redirected to the Screen Unlock settings.
Contact your mobile service provider and say you want to unlock your phone. Your service provider will review your account to confirm you meet all requirements to have your phone unlocked for free. You may not be eligible to unlock your phone if you owe money or have not fulfilled the service contract.Can I SIM unlock my phone myself? ›
Unlock The Phone On Your Own
First of all, you have to turn off your mobile phone and take out the SIM card. Then turn on the device without the SIM card and wait for it to show a message with the instruction to insert the SIM card. From that moment you will need to write the IMEI code to unlock the phone.
The Code 37 error is one of several Device Manager error codes that basically mean that the driver installed for the hardware device has failed in some way.
What is the use of unlocking bootloader in Android? ›
Unlocking the Bootloader allows you to install custom firmware on your Android phone and gives you full access privileges to make modifications to the phone. Such modifications could involve changing some of the pre-loaded software, or could even include replacing the entire operating system.What is the difference between locked and unlocked bootloader? ›
By default, most Android devices ship with a locked bootloader, meaning that users can't flash the bootloader or device partitions. If needed, you (and device users with Developer options enabled) can unlock the bootloader to flash new images.What is Smart Lock? ›
Smart Lock allows you to keep your device unlocked while it's on you, add locations where your device stays unlocked, and add Bluetooth devices that will keep your device unlocked while they're connected.What is the most secure way of unlocking a smartphone? ›
Fingerprint sensors are now so common you even get them in many entry-level phones. It has become the preferred unlock method for many. It isn't hard to see why. It's fast, intuitive, and secure.
- Connect your Android phone to your computer.
- Open a command prompt window in your ADB installation directory.
- Type “adb shell rm /data /system /gesture.key”, then click Enter.
- Reboot your phone, and the secure lock screen would be gone.
Contact your carrier
Only your carrier can unlock your iPhone. Contact them and request an unlock. After you submit the request, it might take a few days to complete. Contact your carrier to check the status of your request.
The PIN or password is used as part of the key to decrypt the data stored on an encrypted Android device.What is unlock vs root Android? ›
Rooting is distinct from SIM unlocking and bootloader unlocking. The former allows removing the SIM card lock on a phone, while the latter allows rewriting the phone's boot partition (for example, to install or replace the operating system).What is master key password? ›
The database master key is a symmetric key used to protect the private keys of certificates and asymmetric keys that are present in the database. When it is created, the master key is encrypted by using the AES_256 algorithm and a user-supplied password.What is the hard reset code for all phones? ›
Open the dialer/phone app on your device and input this code: *2767*3855# step 3. After that, follow the on-screen instructions to reset your device.
What is master password lockout? ›
Master Password Lockout.
It can be enabled from BIOS Setup. Once enabled, the Admin, System, and HDD passwords are protected from being reset using recovery password. (
Hide Caller ID: *31#
The caller might have hidden the ID intentionally or sometimes it can be accidental. If you want to hide the caller ID dial *31# and press call button.
What does dialing *#21# actually do? When you dial *#21#, you are, in fact, activating a feature access code that quickly tells you the status of call forwarding for your phone. It's a quick way of seeing what, in the case of this particular 'setting interrogation code,' your call forwarding settings.What is Android master key? ›
Summary. Exploit:Android/Masterkey identifies code designed to exploit a known vulnerability in the way the Android operation system verifies the authenticity of an app.Is there a master key for all master locks? ›
No. Without the key number, there is no way for Master Lock to know which key will open your lock. There is not a master key that will open all Master Lock products.What is the master reset code for Android? ›
For the Samsung devices, the Android factory reset code is *#*#7780#*#*. In case the other code does not work, there is a custom reboot code which is *2767*2878#.What is the code for network reset? ›
For newer Android devices
Enter *# *# 72786 #* #* into the dial pad. Don't tap the call icon or try to connect.
A backdoor in a login system might take the form of a hard coded user and password combination which gives access to the system.How to unlock BIOS without password? ›
BIOS passwords cannot be recovered.
If you have forgotten one of the passwords that is set in the BIOS, resetting the CMOS or NVRAM helps reset the BIOS to factory default settings and remove the passwords from the BIOS.
The CMOS battery looks like a watch battery, and it powers the motherboard even when the computer is unplugged. This might be how the password is stored on your motherboard along with the system time and your computer's BIOS settings. Removing and reinserting the battery will clear all of these settings.