Guide to unlock bootloader & flash custom recovery

Notes -

• There are two methods to unlock bootloader, official and unofficial. Here, both methods are described.

• Official method will void your warranty, block your Stock ROM OTA updates and you won't be able to relock bootloader.

• Unofficial method also voids your warranty and Stock ROM OTA, but you will be able to relock bootloader. Once you relock bootloader than you warranty and stock ROM OTA updates will be restored.

• Unofficial method is recommended, use official method only if unofficial method isn't working for you somehow.

• The methods discussed in this guide are tried and tested many times, still if you somehow manage to fuck up your device than I'm not responsible.

❈ Unofficial method to unlock bootloader -

• Video tutorial -

• XDA thread -

If you don't understand Hindi than no worries, there are English instructions available on this XDA thread. Follow this thread till bootloader unlock process only.

❈ Official method to unlock bootloader -

• Instructions -

1) First download official unlock tool apk from this link.

2) Backup all contents of your internal storage & data (apps) to PC/SDCard as internal storage and all your data (apps) will be wiped in this process.

3) Just install the app, follow instructions given in the app. Internet connection is needed for this app to work so make sure you have connected to mobile data/wifi.

4) Select agree for the agreement that appears than tap on "PRESS TO UNLOCK YOUR DEVICE", your device will now reboot to fastboot mode.

5) Slightly long press on power button, your device will be formatted and it will reboot with bootloader unlocked.

❈ Guide to flash custom recovery (TWRP) -

In this process your device will be formatted so backup everything in internal storage and all your apps to PC/SDCard.

• Video tutorial -

• Instructions -

1) Recommended custom recovery is latest
official TWRP 3.3.1.0, download from this link.

2) Download ADB Drivers from here and install in your PC if not done already.

3) Copy recovery .img file that you downloaded and paste it in C:\adb folder.

4) Enable USB debugging in phone if not done already.

5) Connect phone to PC using USB cable (in a USB 2.0 port), check in This PC>Properties>Device Manager if "ASUS" device appears there. If "ASUS" name doesn't appear than right click on whatever device that appears and update device drivers using internet.

6) Now go to C:\adb folder, open an elevated cmd/powershell window here by using shift + right click. Use command adb devices, if a pop-up appears in phone than click on allow. Use command adb devices again a "serial number device" will appear. This means device connected to adb interface successfully.

7) Now use command adb reboot bootloader, your phone will reboot to fastboot mode.

8) Check device connection in fastboot mode by using command fastboot devices, "serial number fastboot" should appear.

9) Now type command fastboot flash recovery
after this a single space and than drag recovery file and drop on cmd/powershell window and press enter. Flashing recovery process will show on PC.

10) After flashing recovery process completed, don't reboot your phone to system, if you do this than TWRP will be replaced by stock recovery. Instead reboot into recovery using volume down + power button. Be careful with buttons, if you boot into phone than TWRP will be gone and you will have to flash it again.

11) After entering into TWRP, don't enter any password, don't tap on any option, just swipe in the bottom. Now, you have to decrypt internal storage, for that go to Wipe>Format data, type "yes" and enter. This step is necessary and can't be avoided.

12) Now you have 2 options, flash custom ROM or stay on stock ROM. If you flash any custom ROM than TWRP will stay as your reocery. But if you want to stay on stock ROM than don't reboot right now, because if you reboot to system than TWRP will be replaced by stock recovery. This is due to force encryption.
To disable force encryption and to retain TWRP on stock ROM you will have to flash two files.

13) Download this force encryption disabler file, now connect phone to PC, copy this file to phone's empty internal storage. If device is not showing in PC after connecting or if you are not able to copy-paste files than go to mount option in TWRP and than tap twice on "Disable MTP".

14) Now go to Install section in TWRP, select internal storage and than flash force encryption disabler file.

15) Wipe cache/dalvik and reboot system.

This way you can retain TWRP in stock ROM.