There are many reasons why you would want to hard reset your phone, however, please read the warning before proceeding.
Warning: doing a hard reset of your Samsung Galaxy S5 Mini G800H will delete all the data you have accumulated: photos, videos, contacts, and apps. So, please make backups before a hard reset.
Here are 2 really easy ways to hard reset your Samsung Galaxy S5 Mini G800H:
I — Samsung Galaxy s5 mini factory reset
1. Shut down your device;
2. Press and hold at the same time the following buttons: “Home” + “Power” + “Volume up”;
3. You will enter the recovery menu.
4. Find and chose “wipe data/factory reset” by Volume btn. Press the “Power” key to confirm;
5. Confirm the process by selecting “Yes” on the next screen;
6. Last but not least, select “reboot system now”.
In the second method, you can use the Android menu. Follow the next steps to hard reset s5 mini
1. Go to “Settings“;
2. In the “Personal” section, select “Backup and Reset“;
3. Select “Factory data reset“.
4. Factory reset > Reset Phone > Erase Everything
5. (May ask for a password or pin code if you have one before)
After proceeding with all of those methods, please wait until the phone restarts.