To hard reset or simply factory/master reset is to restore your device to its initial state. The initial state is the state it was when leaving the factory. There are many reasons that would make you decide to hard reset your Sony Xperia E4.
Generally, the following are the best methods you can use to hard reset Sony Xperia E4.
Hard reset Sony Xperia E4 using the buttons:
1. Make sure the battery is full
2. Backup your necessary data
3. Power off
4. Long press the Power key + Volume Up keys together until a new service menu appears
5. Go to factory reset by using the Volume buttons and confirm it using the Power button
6. Phone will hard reset
Sony Xperia factory reset by Using menu
To hard reset your Sony Xperia E4 using the menu,
1. Power on the E4
2. Make sure the battery is full
3. Go to phone menu > setting > back up and reset > factory data reset >then reset the device
4. Select erase everything
5. Phone will factory reset
Sony Xperia hard reset code
To hard reset your Sony Xperia E4 using code
1. Make sure the battery is full
2. Backup your necessary data
3. Power ON
4. Go to dialer and type the following code; *#*#7378423#*#*
5. On the new menu, select customization settings, then reset customization, then confirm
6. Phone will hard reset