How can fix my iPhone to work?

Hello!

I have tried to make this Iphone 5 work like normally but its impossible. It's my friends phone. Here's the deal. If I hold the power button on then the display starts to work and there comes the cable and the Itunes logo. As I now know I need to connect to the Itunes. I did it and then it said theres something wrong with the Iphone and they gonna update it and recover it. I agreed with it and it started to download the new IOS update or something like that. But as I got bored waiting for it to finish the connection lost with the phone and the PC and then the hole thing started again. I have done researches but I haven't found a solution. Please help me.