This wikiHow teaches you how to use ADB (Android Debug Bridge) on Windows to lock the Android bootloader. Warning: This action will most likely format the device. Back up your data first!
Step
Part 1 of 2: Installing ADB
Step 1. Start a web browser on the computer
This guide does use a Windows computer. However, the process may be pretty much the same on a Mac
Step 2. Visit
Step 3. Click ADB Installer v1.4.3
As of August 16 2017, this is the most recent version. If it says "Latest version" next to a version, click the link.
Step 4. Click Download
It's a large, green, oval-shaped button. The computer will download a zip file containing the installer, with the extension “.exe”.
Step 5. Double click the file you downloaded
Doing so will open the contents of the zip file.
Step 6. Double-click the file that has the ".exe" extension
The file name will be similar to this: " adb-setup-1.4.3.exe " (depending on the version). A command prompt screen will open, asking if you want to install ADB and Fastboot.
Step 7. Press Y
After that, you will be asked if you want to install the whole ADB system.
Step 8. Press Y
You will see a message saying that the device driver will be installed.
Step 9. Press Y
A few moments later, the computer screen will display the Device Driver Wizard.
Step 10. Click Next
Step 11. Click Finish
Now ADB is installed on the computer.
Part 2 of 2: Locking the Bootloader
Step 1. Connect the Android device to the computer using a USB cable
If your device does not include a USB cable, make sure you are using a secure and compatible USB cable.
Depending on the device you are using, you may need to install a driver for the computer to recognize the device. Drivers can be found on your device manufacturer's website
Step 2. Press Win+S key
The Windows search field will open.
Step 3. Type cmd
Matched search results will be displayed, including "Command prompt".
Step 4. Right-click "Command prompt", then click Run as administrator
By doing so, you will be using the command prompt as admin.
Step 5. Click Yes to confirm
A command prompt will be opened.
Step 6. Type adb reboot bootloader, then press Enter key
ADB program will be run.
Step 7. Type fastboot oem lock, then press Enter key
The command will be executed and the bootloader will be locked. If an error message appears, try typing one of the commands below:
- fastboot flash lock
- OEM relock
Step 8. Type fastboot reboot, then press Enter
The Android device will restart and the bootloader will be locked.
