Hello friends! I need help! If you can (any hint help). Windows 7 iPhone 5 - updated itunes - original cables - updated pc drives. I will summarize ... I forgot my iphone at home and it all discharged one day there tried to reload and he was the apple looping. I tried to restore it in DFU mode, and also in recovery mode, but the two modes show the error 21 and can not proceed with the installation of ios. I had this problem a few months ago in the same cases and managed to fix it. I found that the error 21 was appearing for the moment it will install on the iphone ios, he was disconnecting the device ... and to successfully achieve the installation, the device can not disconnect. So it was back to go to restoration screen or dfu (however had already disconnected). And so the error 21. In the first time I gave this error very researched and several people said it was the battery. But I kept trying to fix yourself at home. and got even without changing the battery. I confess I do not remember in detail what I did because I was so excited when I could not pay attention. I remember a friend said to try using TinyUmbrella, and uncheck the option "set hosts to Cydia on Exit" But this option in Advanced, can not remember if it was possible to be check or uncheck. But I was able to make the itunes restore my iphone is that first time! When installing iPhone NOT disconnected and the installation was normal .. it worked several months .. Finally, now again I have the same problem. Error 21, for cases discharged completely. Anyone have any tips? A program (I do not know), to avoid the iPhone restart during the installation ??? Help guys .. to several days trying to solve ... Thanks!