If you ever screw up your Samsung Galaxy S7 or S7 Edge while rooting or installing custom ROMs, there’s an easy way to “unroot” and re-install stock firmware your phone came with.
There are situations where this can come in handy such as if you are going to re-sell it on eBay, return the phone for warranty, or want to simply update to the latest stock firmware on a rooted phone.
Now, this unroot method ERASES EVERYTHING ON YOUR PHONE! SO MAKE A BACKUP BACKUP BACKUP BEFORE FOLLOWING INSTRUCTIONS! YOU HAVE BEEN WARNED!!!
Step 1. Go to Settings->About device and check the model number of your Galaxy S7 or S7 Edge and take a note of it, write it down somewhere.
Step 2. Power off your phone then hold down Volume Down, Center Home, and Power buttons together for about 5 seconds until you see a warning screen like below:
Step 3. Hit Volume Up key to put it into ODIN download mode then connect a micro-USB cable from your phone to your Windows computer. We highly recommend you to use Windows but if you don’t have one/can’t borrow one, you can run Windows on top of VMWare instead.
Step 4. Download ODIN, Samsung USB Drivers, and firmware model for your S7 or S7 Edge.
Unzip both the ODIN and stock firmware zip files.