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.