I Touch 4 will not sync

Hi all I have a I Touch4 running 6.13. I Tunes 11 and my 4s is running the latest version of IOS 7. I am trying to back up and sync to I Tunes on my pc I get to finishing sync and than the system locks up or I get an error message I need to update my device to sync my apps such as find my I phone. Is there away to fix this issue. Thanks John