I will show you easy step to hard reset Samsung Galaxy S3 (i9300).Take note that while hard resetting all of your data including pictures and apps will be lost if you have not backed them up.
- Turn on your phone and navigate to setting icon.
- Scroll down to the last menu at the bottom.
- Click “System.”
- Select the option labeled “reset options.”
- choose “factory data reset”option.
- Tap the last “reset phone” to confirm you want to erase all data.
- Enter a correct pin or pattern and select “yes erase everything” to continue.
- Congratulations you are through! Wait your phone to restart and complete the initial setup.
- Turn off your Samsung S3 GT
- Press and hold home plus volume up key then press the power key
- Scroll using the volume down key and select factory reset/wipe data and accept it by pressing the power key
- Scroll using volume down and select “yes” and accept it by pressing the power button
- Wait patiently for your Samsung Galaxy s3 gt-19300 device to reboot