Nokia Lumia 635 hard reset
1. Turn the power Off.
2. Press and hold the Volume down and connect the charger or the USB cable with PC, for about 8 seconds, you will see an exclamation mark (!) on the screen. Note: If you do not press any of the following keys, then the phone wp8 will starts boot normally.
Then press the keys in this exact order:
1. Volume up
2. Volume down
4. Volume down
Phone will restart, be patient.
resetting your Nokia Lumia 635 from menu
Factory reset Nokia Lumia 635 from the menu
- On the Start screen, tap .
- Tap Settings > about phone.
- Tap reset your phone, and then tap yes.
Nokia Lumia 635 soft reset
Press and hold the power key for over 8 seconds. The phone will reboot.
Update your phone software.