Signed IPSW files can be restored via iTunes. Unsigned IPSWs cannot currently be restored via iTunes.
✗ | iPhone 2G | iPhoneOS 1.1.4 (4A102) | 22nd February 2008 | 170 MB | iPhone1,1_1.1.4_4A102_Restore.ipsw |
✗ | iPod touch 1G | iPhoneOS 1.1.4 (4A102) | 22nd February 2008 | 174 MB | iPod1,1_1.1.4_4A102_Restore.ipsw |