If your phone is unresponsive and you can’t reach Settings icon, you may be able to reset your phone using the hardware buttons.
On Lumia phones (and some others), do the following to reset your phone:
Press and hold the Volume down and Power buttons at the same time until you feel a vibration (about 10-15 seconds).
When you feel the vibration, release the buttons, then immediately press and hold the Volume down button until you see a large exclamation mark.
Once the exclamation mark appears, press the following four buttons in this order:
- Volume up
- Volume down
- Volume down.
Your phone should now reset and restart itself. (It might take a while for the reset to finish.)