Content

• Steps
• Part 1 of 2: How to Install Android Debug Bridge (ADB)
• Part 2 of 2: How to lock the bootloader

In this article, we will show you how to lock the bootloader on an Android device using the Android Debug Bridge (ADB) for Windows.

Steps

Part 1 of 2: How to Install Android Debug Bridge (ADB)

1. 1 Launch a web browser on your computer.
   • The process described here is for Windows, but it is the same for macOS.
2. 2 Open the site https://androidmtk.com/download-15-seconds-adb-installer.
3. 3 Click on ADB Installer v1.4.5 (ADB Installer 1.4.5). This is the latest version as of February 2020. If the word “Latest” appears on another version, click on it.
4. 4 Click on Start now (Download). It's a long green button. The archive (Zip file) with the installer (Exe file) of the program will be downloaded.
5. 5 Double click on the downloaded archive. Its contents will open.
6. 6 Double click the EXE file. It is called "adb-setup-1.4.5.exe" or similar. A command prompt window will open asking whether to install ADB and Fastboot.
7. 7 Press the key Y. Now it will ask you whether to install ADB for the whole system.
8. 8 Press the key Y. You will be asked whether to install the device drivers.
9. 9 Press the key Y. The device driver installer window will open.
10. 10 Click on Next (Further).
11. 11 Click on Finish (To complete). The ADB program is installed on the computer.

Part 2 of 2: How to lock the bootloader

1. 1 Connect your Android device to your computer via a USB cable. If you do not have the cable that came with your device, use another compatible cable.
   • Depending on the device, you might need to install drivers for the computer to recognize the device. Such drivers can be downloaded from the website of the manufacturer of the mobile device.
2. 2 Click on ⊞ Win+S. The search bar will open.
3. 3 Enter cmd. A list of search results will be displayed, in which search for "Command Prompt".
4. 4 Right click on "Command Prompt". Now select Run as administrator from the menu. This allows you to run a command prompt with administrative rights.
5. 5 Click on Yesto confirm your actions. A command prompt will open.
6. 6 Enter adb reboot bootloader and press ↵ Enter. The ADB program will start.
7. 7 Enter fastboot oem lock and press ↵ Enter. The command will be executed, which will block the bootloader. If you receive an error message, enter one of the following commands:
   • fastboot flashing lock
   • oem relock
8. 8 Enter fastboot reboot and press ↵ Enter. The Android device will reboot and the bootloader will be locked.