I am not sure why they are not opening. If you haven't already try rebooting your phone. If that doesn't fix it try factory resetting again after rebooting. If you still can't please follow the directions below to get your phone working again.
Make sure your phone is backing up (under backup make sure texting and apps+settings backup is enabled). Download the windows device recovery tool on your pc (
http://go.microsoft.com/fwlink/p/?LinkId=522381) Install it and open it up and plug in your phone to your pc. Click on your phone and follow the instructions on screen to recover your phone. Once your phone boots back up it should come up with the normal set up page that you get when you first buy a phone.
Hope this helps!!