Signed IPSW files can be restored via iTunes. Unsigned IPSWs cannot currently be restored via iTunes.
✗ | iPhone 2G | iPhoneOS 3.0.1 (7A400) | 31st July 2009 | 240 MB | iPhone1,1_3.0.1_7A400_Restore.ipsw |
✗ | iPhone 3G[S] | iPhoneOS 3.0.1 (7A400) | 31st July 2009 | 312 MB | iPhone2,1_3.0.1_7A400_Restore.ipsw |
✗ | iPhone 3G | iPhoneOS 3.0.1 (7A400) | 31st July 2009 | 241 MB | iPhone1,2_3.0.1_7A400_Restore.ipsw |