1. From the Start screen, tap the Phone tile.
   
2. To block a phone number, touch and hold the desired recent call.
   
3. Tap block number....
   
4. Tap ok.
   
5. Blocked phone numbers will be ignored. To unblock a blocked phone number, tap the Menu icon.
   
6. Tap blocked calls.
   
7. Tap accept.
   
8. Tap blocked numbers.
   
9. Touch and hold the desired blocked phone number.
   
10. Tap unblock.