Hello all, I am using a jailbroken iPhone 3GS with firmware 3.1.2 (7D11) and Modem Firmware 05.11.07. I have jb with Blackra1n and happily used for 3 months. However, I am reaching a point to restore my iPhone as my computer doesn't recognize my iPhone anymore after I installed some apps. The only time my computer will recognize my iPhone is when it is in DFU or recovery mode. After I reboot my iPhone with Blackra1n, the computer will no longer recognize it. I have downloaded two ipsw files (1. iPhone2,1_3.1.2_7D11_Restore.ipsw; 2. iPhone2,1_3.1.2_7D11_Tethering_Patched-installd_Restore) and tried to restore it using iTune (with the "shift restore" method) but unable to do so. I have modified the windows host file and yield a 1600 error with the Tethering Patched ipsw file. As for the Restore.ipsw file, it just can't complete the process after iTune verify my iPhone version. I have also tried using iREB but it just can't turn my 3GS screen into either White or Red. Please help. Many Thanks in advance.