Unlocking the bootloader DELETES ALL DATA from your device (including apps, contacts, messages; etc). So do backup anything important before proceeding.
- Download and install ADB and Device Drivers on your Windows PC.
- Download the root files for Yureka and extract them to a folder.
- Turn off your Yureka by holding the power button and choosing Power off.
- Press and hold the Volume Up key and connect your phone to the PC using a USB cable. Keep the Volume up key pressed till you reach the Fastboot Mode.
- On the PC, open the folder where you extracted the Yureka root files (downloaded in step 2).
- While holding the SHIFT key, right-click on a blank area inside the folder and choose Open command window here.
Copy and paste the following command into the command window that opens:
fastboot -i 0x1ebf oem unlock
Unless the command shows an error, your bootloader is successfully unlocked.