Just to share my experience to others please follow these steps

1. Turn Off your device by pressing and hold Power button for 5 seconds then you will see a good bye animation and the screen will be shut off
2. Press Windows button and Hold
3. Press OK button and Hold
4. then Press Power button and hold and then a hard reset screen appears and just follow the instructions

IF its failed, try to change the step 4 by press the reset button using your stylus

Good Luck

Cara melakukan Hard Reset pada O2 XDA Stealth, ikuti langkah diatas

please send this link to your friend.