Iphone 4s blocked in recovery mode

Hi every body,

I have an Iphone 4s (16Go-White) and after some problems with my operator network, i've decided to restore it with Itunes.

When i did it, the action stop nearly 70% 80% on the loader under the apple, and the message with "Error 1" appear.

My host file is OK concerning the line gs.apple.com.

I've made the operation on tree differents computers and it's always the same.

So, actually it's impossible to use the device and restore it.

I don't know what to do, so if you have an idea...?

Thaks for your answers!