1. Delete the previously down*loaded software update file which you will find in this loca*tion depend*ing on your system: Mac: /users//Library/iTunes/iPhone Soft*ware Updates Windows XP: System Drive:/Doc*u*ments and Settings/Application Data/Apple Computer/iTunes/iPhone Soft*ware Updates Windows 7: System Drive:/Users/Your Username/App Data/Apple Computer/iTunes/iPhone Software Updates If you faced the error while upgrading your iPad or iPod, the last location path will change: ../iTunes/iPod Software Updates or ../iTunes/iPad Software Updates 2. Now, restart iTunes & begin the update again. This time iTunes will download a fresh copy of software update file. 1. Re-download the IPSW file. 2. Now, restore to this newly downloaded IPSW file via iTunes. Best of luck.
I had same problem with my iphone 4s.I restored my iphone with previously downloaded latest ipsw file via itune. Ok let me explain: 1-Connect your iphone to itunes. 2-Itunes recognise your iphone is in recovery mode. 3-Now one button highlighted in itunes-Restore iphone. 4-If you have downloaded ipsw file then click restore button with keyboard SHIFT key(Win) or only click restore (itunes will download and install latest ipsw file). I hope all is well..