My friend gave me his iphone 3gs. I plugged it into the computer, itunes opened and it began to recover. When it's just about to finish it gives me the error 1015. Error 1015: This error is caused by attempts to downgrade the iPhone, iPad, or iPod touch's software. This can occur when you attempt to restore using an older .ipsw file. Downgrading to a previous version is not supported. To resolve this issue, attempt to restore with the latest iPhone, iPad, or iPod touch software available from Apple. Can someone please help me with this?