I have unlocked the bootloader with windroid, then I flashed TWRP recovery, then I flashed supersu zip file through TWRP to root my phone. Now I want to Unroot and relock the bootloader, but when I press 'Full Unroot' option in supersu it automatically reroots after a reboot. How can I unroot and relock the bootloader in my phone?
I don't know if it works the same way for HTC Desire 820 @Suriya, but I have also found another procedure for unrooting.
Download Universal unroot apk for HTC Desire 820.
Connect your device to your PC using the USB cable.
Copy the Universal unroot apk to your SD card.
Once it’s been copied, disconnect your device from your PC.
Head to Menu>>Settings>>Security on your device and enable the Unknown sources option.
Open the File Manager app on your device and install the app you copied earlier to your device.
Once the app’s been installed, launch it from your App Drawer.
Hit the button marked- “Temp. un-root (keeps backup).” Your phone is now temporarily unrooted. If you’d like to make it more permanent, click the “delete su backup” button. You can then click “Restore Root” whenever you want to bring the root back.
Download the stock Android ROM available here - http://www.mediafire.com/file/b9tpx11ge983q6b/HTC_Desire_820G_Plus_Dual_SIM_MT6592.zip
Follow the steps mentioned below.
Download and install HTC USB drivers from https://phoneusbdrivers.com/htc-one-usb-driver/
Switch off your HTC Desire 820G Plus Dual SIM smartphone and remove the battery (it is removable).
Go to the extracted folder in Step 1 and open up the SP Flash Tool sub-folder. You will find Flash_tool.exe file in it. Launch it.
Once SP Flash tool is launched, click on the Download tab.
Click on "scatter-loading" button in the Download tab.
Click on Open Scatter File and select the scatter file from Step 1.
Click on the Download button to start the flashing process.
Connect your HTC Desire 820G Plus Dual SIM Android device to your computer through original USB cable (without battery – if it is battery removable) and press volume up or volume down button.
The flashing process will begin momentarily, and it will get completed in a minute or two. Once it is over, you will see the Download OK green ring in SP Flash Tool.
Close SP Flash tool on your computer and unplug your smartphone.