Itunes error code 20

Hello everyone,

My iPhone is V1 firmware 2.0 and would like to downgrade to 1.1.4 to implement the guide pwnage firmware 2.0 on windows. When I try to restore the phone with iTunes 7.5 and firmware iPhone1, 1_1.1.4_4A102_Restore.ipsw, iTunes gives me the error 20. So my phone is useless now, is anyone ever had this problem?

to remove Itunes error code 20 while firmware upgrade, open iTunes, you should hold the "Home" and "Power" for 7-8 seconds until the iphone is not sync. Once the screen stop signs of battery life, you need to delete the "Power" but continue to keep the "Home" is up to 10 seconds. Once iTunes detects the iPhone and you can safely change the firmware.

Once downgraded iTunes, you put your iPhone into DFU mode. Then you click on "Restore" in iTunes holding the Shift button pressed. You select the firmware 1.1.4 above then you let iTunes restore your iPhone. Once restored, you use ziphone by clicking on "Do it All". You can also use ZiPhone, At my iPhone using the downgrade went smoothly and I unlocked my iPhone and unlocked with firmware 1.1.4.

The problem is that you have the iphone in DFU mode, you have to endure longer pressing the keys. Press the HOME and POWER button at the same time, 10 seconds turns off (if you're on windows beep will sound), continue pushing until you hear the beep again or recognize windows recovery mode, then you are in DFU mode (with black screen). The error 20 always comes when the image of itunes and the headphones on the iphone.

If you have an iPod Touch and for some reason the firmware update to the latest version and want to return to the older to do Jailbreak and be able to install applications, there is a very simple method :

1. Turn off the iPod with the red slider.
2. Connect it via USB and open iTunes.
3. Press both buttons to turn on and the Home for 10 seconds but do not let go.
4. Release the power button and hold down the Home button for 10 seconds and then release.
5. iTunes will recognize your iPod in restore mode at this time going to restore to version 1.1.1. or 1.1.2.
6. When click on the restore button press the Option key on Mac or Shift on Windows to choose which firmware to install.