Is your phone not working properly? Did you change your password and your phone isn't logged in? Wipe the slate clean by resetting it!

 - On the phone number pad, press and hold the "#" and "*" (pound and star) buttons. After about 10 seconds, a message will appear asking about Factory Reset. 
 - Approve the reset. The phone will go through a reboot and reset process. This will take several minutes. 

 - When finished, you will see prompts to set your preferred language and time zone. When done with your selection, select the check mark in the upper-right of the screen

 - The phone will then come to the screen to sign in. You can use the code on Microsoft's website to sign into the phone again.