If you do not connect to the wifi layer system is wrong, try a FREE Wifi and sia even one so connected, the safest thing is this evil system, the only thing left is to do a Hard reset, but that erases all your infomarcion sure to keep your contacts on your chip and your files on your memory stick.
Once this is assured bowels:
Settings> Backup and restoration> factory data reset.
You click on accept and expect the phone is restarted, the process takes, so be sure to do so before the battery is preferably filled, then just wait, the phone gives you the bienbenida and make your settings and then test the connection.