Tutorial How To Unroot Samsung Galaxy S3

The new Samsung Galaxy S3 has huge resources- Custom ROM and Application. Still, you should know that when you buy it, the operating system doesn’t allow you to make use of its full power. If you root it then you can explore more of its performances tweaks. The CF Root is the first rooting method is simple and easy use to root your Galaxy s3 with only few click (Tutorial How To Root).
But, if you want to send your Samsung Galaxy S3 back in for warranty reasons or maybe you just want to start over with a stock device. Here’s the quickest way to unroot the device and get it back to fully stock. There still not has any Unroot Tools that allow you to unroot your Galaxy S3 with simple one click. To unroot Galaxy S3, you need to Reset the Flash Counter and then manually flash stock ROM via Odin.
Reset Flash Counter:
When you root your Galaxy S3 via CF Root  Method, this flash insecure kernel will increase the Flash Counter. For Example, when you boot into download mode (press>Volume Down + Home + power button):
Before Root or flash insecure kernel

ODIN MODE
PRODUCT NAME: GT-i9300
CUSTOM BINARY DOWNLOAD: NONE
CURRENT BINARY: SAMSUNG OFFICIAL

After Root or flash insecure kernel

ODIN MODE
PRODUCT NAME: GT-i9300
CUSTOM BINARY DOWNLOAD: 1
CURRENT BINARY: SAMSUNG OFFICIAL

So you need to reset the Flash Counter. You can refer here the complete tutorial + Video on how to reset Galaxy S3 Counter.
Flash Original or Stock Firmware
After reset the counter, now you need to install or restore back your Galaxy s3 original Firmware. For your info, here is the different info show in the Downloading Mode after you Root and flash Custom ROM into Galaxy S3:
Galaxy s3 with Original ROM
ODIN MODE
PRODUCT NAME: GT-i9300
CUSTOM BINARY DOWNLOAD: NONE
CURRENT BINARY: SAMSUNG OFFICIAL


Galaxy S3 with Custom ROM + Rooted

ODIN MODE
PRODUCT NAME: GT-i9300
CUSTOM BINARY DOWNLOAD: 1
CURRENT BINARY: CUSTOM

So, now you need to flash Samsung official ROM into your Galaxy s3. Before Flash,  check and make sure that download with your local version firmware on you region. You can refer here on how to check the firmware version and download the original stock firmware. Then follow the guide below to flash the original firmware into your Galaxy s3:
1. Downloadand install Samsung Kies on your PC. Restart your PC after installation complete.
2. Download the S3 firmware (.zip) and then Extract the file (now you will get .tar file) into your PC.
2. Go Setting >Developers option to enable USB Debuging on your Galaxy S3 and then Power off your  Galaxy S3.
3. Press your Galaxy volume up + Power Button + Home Button to enter Downloading Mode.
4.  Open Odin (download Link) on PC, then connect your S3 to PC via USB connect USB.
5.  Make sure Odin Detect your Galaxy S3 (How to know).
6.  Press Odin PDA, then select the  downloaded firmware (.tar).
7. Now click Odin Start button  to Flash the firmware into your galaxy S3.
8. That all! Your Phone will reboot once the firmware complete flash into your S3.

Now you boot into Downloading Mode, and you can see that your Galaxy S3 will show that:
ODIN MODE
PRODUCT NAME: GT-i9300
CUSTOM BINARY DOWNLOAD: NONE
CURRENT BINARY: SAMSUNG OFFICIAL
If you have any question about this tutorial, you can leave us a comment. We will try the best to answer your Questions as soon as possible!