I update my I phone3Gs , but when I go back to restore it from my back up its asking me password to unlock the backup but I did not mention or add any password please adivse
If you did not enable backup encryption and it is now asking for a password, the backup is corrupt.
There is no way to remove the "password".
Restore the device as new and sync back your content. Everything should already be in iTunes.
Retrieving data ...