These are the instructions to root OnePlus 2 using the TWRP recovery on Windows Computer.
Requirements: Your smartphone should have atleast 20-30 percent of battery to perform the rooting process.
Step 1: Follow the step-by-step instructions to unlock bootloader on your OnePlus One 2 Device.
Step 2: Once you have successfully unlocked the bootloader on OnePlus 2, then you need to install custom recovery (i.e TWRP or CWM recovery). For that you have to connect your device to the computer first then follow the below steps.
Step 3: Download SuperSU (latest) and move it to the root of the Phone SD memory.
Step 4: Download and install the Minimal ADB and fastboot Tools on your computer.
Step 5: Download TWRP recovery (tested working) on your computer.
Step 6: Now, move the TWRP recovery file to the Minimal ADB and Fastboot folder (i.e C:Program FilesMinimal ADB and Fastboot).
Step 7: Now, Open MAF32.exe from the Minimal ADB and Fastboot folder.
Step 8: Now, you need to boot into the Fastboot Mode. To Boot into fastboot mode, press and hold the Volume UP and Power Key (for 4-5 seconds) and release all the the buttons when you are able to see the fastboot logo on the screen.
Step 9: Give the Following Command: fastboot devices
The above command helps to know the list of attached devices to the computer.
Step 10: Now, Give another command: fastboot flash recovery oneplus2-twrp.img
Step 11: Now, you will be able to see some processes on your Device screen.
Step 12: Now, you need to boot into the TWRP recovery Mode. To Boot into twrp recovery mode, press and hold the Volume Down and Power Key (for 4-5 seconds) and release all the the buttons when you are able to see the twrp recovery screen.
Step 13: Once you have booted into the TWRP recovery mode, Tap on the Install and select the SuperSU package that you have moved to the Phone SD in Step#3.
Step 14: Now, reboot your Device from the TWRP recovery.
Step 15: Once your Device is restarted you will be able to see the SuperSU icon in the Menu. Which confirms that you have successfully rooted your OnePlus 2.
Optional: You can also verify the root status of your device by using the Root Checker Application.
[*] No data loss process: Your Personal Data including contacts, pictures, videos, music wont be affected using the above method. In short, no data loss process.
[*] Big thanks to Chainfire for their SuperSU file for OnePlus 2, without this tool the above tutorial was not possible.