Restarting your Phone Soft reset 

Occasionally, you may want to restart your phone, for example, when
a program is not performing properly or the phone does not respond to
any keypresses.
To restart the phone

  1. Remove the battery.
  2. Reinsert the battery and turn on your phone.

Warning! If the phone is restarted while a program is running, unsaved
work will be lost.

Resetting your Phone Hard reset 

Resetting your phone will remove all the data from its memory which
include contacts, tasks, calendar appointments, and more, and restore
the phone back to the factory default settings.
To reset your phone

  1. Click Start > Accessories > Clear Storage.
  2. Follow the on-screen instructions to reset the phone. The phone will restart after it has been reset.