1. Turn off the phone completely.
2. Press and hold both Volume UP (and HOME) + power on the phone.
3. When Android Recovery menu screen appears release all keys.
4. Navigate and highlight
wipe data / factory reset using the Volume down key and press power.
5. Navigate and highlight again to
Yes - delete all data and press power.
6. All data will be lost! Before doing a hard reset backup all important data.
After hard reset is done select
Reboot system now. Press power to reboot the phone.
Another way to reset your Samsung Galaxy S7 active is to enter the reset code on dial screen.
On dial screen enter this Samsung Galaxy S7 active reset code: *2767*3855#
All data will be lost.
or
Use Samsung Galaxy Samsung Galaxy S7 active Backup and reset function
Go to
Settings-Backup and reset - Factory data reset: Reset settings to the factory default values and delete all data.
Your device freezes or has fatal errors
If your device freezes or hangs, you may need to close applications or reinsert the battery and
turn on the device to regain functionality. If your device is frozen and unresponsive, press and
hold the Power button for more than 8-10 seconds to reboot.
If this does not solve the problem, perform a factory data reset. On the Applications
screen, tap
Settings -/Backup and reset/ Factory data reset / Reset device / Erase everything. Before performing the factory data reset, remember to make back-up copies of all important data stored on the device.
More..... http://www.hard-reset.com/samsung-galaxy-s7-active-hard-reset.html