How To Fix Error 14 in iTunes?

Note: This solution works for all iOS versions (iOS 5 & earlier)
If you’re upgrading to iOS 5 via iTunes directly:

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 ******** 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.
If you’re trying to restore by using the downloaded iOS 5 IPSW file:

1. Re-download the IPSW file.
2. Now, restore to this newly downloaded IPSW file via iTunes.
If you have any questions or difficulties, feel free to ask below.