Here's how you can reboot your Android Jelly Bean device into safe mode. This is useful if you have a bad piece of software that is affecting system stability.
1. Long press the power button.
2. Long press the power off button.
3. Choose the OK option.
4. Your Android device will reboot in safe mode, and all third party apps will be disabled.
For more, see the original article at the link below.
50 Android Jelly Bean tips, tricks and hints | Tech Radar