Ok I need to get some things clearish in my head.
Does this mean that all data has been lost on the hard drives?
You say that the system is trying to boot from the smaller drive, is it possible to tell it to look for the larger drive?
I don't mind reinstalling the OS, but I'm not shure how to do it, my upgrade was a download from the Microsoft website so I guess that the activation code I have will still work, but how do I get the OS onto a system which will not get past the screen you have seen, how do I tell it where to look for the OS.
Also I have no idea how to set up the partition you mention.