Microsoft Lumia 550 hard reset

This method is called HARD RESET and will reset your Microsoft Lumia 550 to factory settings by using a keys combination without requiring the phone to be power on. Use it if you forget your security code, password, pin or pattern, if your Windows is running slow or if you have various problems with the phone software.
--
This method will not upgrade or downgrade the firmware version of your Microsoft Lumia 550 and it will NOT UNLOCK the network lock. This method does not reset the PIN code of the SIM card.
--
Warning!
--You do this at your own risk !Make sure your phone battery is fully charged!
--Take your sim card and memory card from the phone before the reset!
--All data will be erased from your Microsoft Lumia 550 storage, including your Microsoft account, system and app data, device settings, downloaded apps, music, pictures, all other user data.
--Please, if you can, make a backup before!