iPhone 4s stuck in recovery mode, error 29

Hello,

I got an iPhone, that wont start up and stucked in Recovery Mode since I was trying to restore it, because I had some problems with the software.

iPhone was working without any problems, before restoring.

What I already tried?

-changed PC

-changed iTunes version

-restore while in DFU mode

-change battery (according to some sources, it was the problem, didnt help in my case)

-configured hosts file

-tried different usb port

-tried different usb cable

As you can see, I tried many things, to solve this problem, but I still get every time at about 70% of restoring progress the error 29.

I just dont know, what I can do.