Sometimes people elect to unchain the system internals with root access so they can begin installing custom ROMs, rooted applications and custom firmware. If you decided to take your device away from the stock version of Android with a stock recovery, then you might be looking to return things back the way they originally were before you started playing around. It’s one thing to unroot your device, but just because you have technically taken root access away doesn’t necessarily mean you have successfully removed the custom recovery, Thankfully, though, I can show you how to unroot and flash the stock recovery back on the OnePlus One smartphone so the custom recovery system is gone.

REQUIREMENTS 

• The following guide is only working for people with a Windows-based computer. The reason being is the toolkit we are using is only for Windows. Do not try and run this package on Mac OS X or Linux machines.
• Enable the Developer Options from the About Device menu by tapping on the build number seven times. Now go back to the Settings app and open it again. Tap the Developer Options and enable the USB Debugging Mode from inside.

HOW TO FLASH A STOCK RECOVERY ON THE ONEPLUS ONE

1. Download the version of Java for your operating system from this page.
2. Download the OnePlus One toolkit from here.
3. Follow the steps to successfully deploy Java scripts on your computer.
4. Click the executable toolkit file so it’s running on your computer.
5. Choose to install the latest ADB drivers from the menu.
6. Now click the Enter Fastboot/Recovery Mode option.
7. Click on Flash Recovery, followed by the Stock recovery.

Now the toolkit will take over and flash the stock recovery as intended. Just sit back and wait until it finishes. Do not touch anything and you’ll get a message on the screen when it’s done. Now you can use the stock recovery for flashing the future over the air updates and accessing features such as the factory reset. Remember that applying hard resets does wipe your phone so you must backup the device before doing that.