Hi, Rosanna.
Thank you for visiting Apple Support Communities.
I would first try a reset of the device. To reset a device, press and hold both the Sleep/Wake and Home buttons for at least ten seconds, until the Apple logo appears. You may need to attempt this multiple times.
iOS: Turning off and on (restarting) and resetting
http://support.apple.com/kb/ht1430
If the issue persists, you may need to attempt a restore on the device via forced recovery.
iOS: Unable to update or restore
http://support.apple.com/kb/HT1808
Regards,
Jason H.