okay, we will have to do a factory restore now. First you will need to be sure that you have your google back up enabled. Open the app drawer, and choose the Settings
In the Settings screen, navigate to the User and Backup section, and choose Backup and reset. If your settings screen is set to tab view, this section can be found under the General tab.
If your Settings screen is in grid view, all you have to do is scroll down the list to find the User and Backup option.
Next, tap the Factory data reset option under Personal Data.
This reset operation will erase all the data you have on the phone, including your internet accounts, downloaded apps, app data, system settings, and will revert your phone to its original state. Since the deleted information cannot be recovered, make sure you have backed up all your important data before continuing. Depending on the type of data you want to back up, you will need to use different apps available from the Store to do the task.
When you are sure that it is safe to do a reset, tap Reset device.
In the next screen, tap Delete all, and wait for the phone to complete the reset operation. The next time the phone boots up, you can set it up as usual.