IPOD Mini 1. Gen Stuck at Bootloader after Utility Installation

[hibert42]

Morning,

I suprisingly got an Ipod Mini 1. Gen and even more suprisingly there was, of course , a custom Firmware for it. Nice!
However, after downloading the Rockbox Utility and running the installation.... well, not much is happening.

My OS is Windows.

At First the Apple Logo shows up and the Pod is stuck there.
I can, however, press the left button... and now A screen is shown, that says

Rockbox boot loader
Version: v4.0
IPOD version: 0x0004001

And thats it, nothing happens....

What is happening here or... what is not happening?

And also, the Ipod doesn't show up in windows anymore, when I plug it back in.

Is everything lost?
Can anyone point me in the right direction?