multiple system images

I now understand the system partition is always installed on the first active partition, in my case disk 0.

What I still like to understand is, why does it install the boot partition (Windows 7) on my disk 1? Is this to make the computer easier to recover in case of a failure?

zx81

zx81,
I don't see anything wrong with what Windows did with the partitions based on your screenshot. I wouldn't say that is ideal but it works... If you don't like it disable the hard drives you don't want Windows to see during install. (i.e. remove power to them until install is complete) I've uploaded a shot of what my drive configuration looks like in my PC.