iPhone 4 won't update past 5.1.1

[mmwies]

I just purchased a used iPhone 4 and it times out every time I try to update. I have it plugged in to a/c power and am connected to wifi. Thoughts?

 

[willerz2]

Plug the device into your computer with iTunes 11.1 or above installed. Backup the device (assuming there's data you want to keep). Click the restore button, let iTunes download the 7.0.6 IPSW, let it restore.