Hard Reset SONY Xperia S LT26i

First method:

1. Press Power button until your phone is on.
   
2. Next go to Settings -> Backup & reset -> Factory Data Reset -> Reset Phone -> Erase everything.
3. Confirm that operation.
4. Done!

Second method:

1. Download program named flashtool from Sony website:http://developer.sonymobile.com/services/flash-tool/
2. Then check, that you have installed drivers for your USB data cable.
3. Now turn off your handset.
   
4. Afterwards press and hold Volume Down, and connect to USB cable.
   
5. Accept all informations.
6. The end.

Third method:

1. Switch off your phone.
   
2. Then hold and press together Power button + Volume Up + Camera key for about few seconds, or until you see menu of your screen.
   
3. Now you will see Factory reset menu.
4. From this menu choose option Erase everything.
5. Done!

Fourth method:

1. You should first download and install program PC Companion.
   * In example from here: http://www.sonymobile.com/gb/tools/pc-companion/
2. If all went well, you will see window with 4 options.
   
3. Next click "Start" under the name "Support Zone New!".
   
4. Wait until the process of the installation is completed.
5. Now you should see window with in example option "Phone / Tablet Software Update".
   
6. Accept this option -> click "start".
7. Then click "repair my phone / tablet".
   
8. Please follow all instructions, and confirm that.
   
9. Read "Inportant information", and confirm.
   
10. Afterwards PC Companion is "preparing computer for software update".
    
11. Next select your phone / tablet model.
    
12. Follow steps, which you see in new window.
    
13. That's all.

Sixth method:

1. Power off your phone.
   
2. Now power on, and when you see that LED notification light turn pink (or any other color), then start pressing the Volume Up or Volume Down button until you see Recovery Mode.
3. From the menu choose option "wipe data/factory reset" using Volume buttons to navigate, and Power button to confirm option.
4. Next select option "Yes -- delete all user data".
5. In the end confirm operation "reboot system now".
6. Good job!

WARNING !
Hard Reset will erase all of your data
All described operations you are doing at your own risk.