Vista - "Windows cannot format the system partition on this drive"

Can anyone help?

I have reinstalled Vista today. I have 2 drives and installed Vista on C.

I want to format D but get the message "Windows cannot format the system partition on this drive".

Why is the System partition installed on D? Can I move it to C so I can format D?

I don't really know what all this means - I understand from a quick google search that System & Boot partitions can be on separate drives and this is determined by BIOS.

In "Disk Management", D is listed as Disk 0 and C is listed as Disk 1 - could that have something to do with it?

It's not the end of the world if I can't format D but I would like to and I don't like not understanding what is going on!

I'd be very grateful if someone could help. I don't mind reinstalling if I have to and I could swap the cables on the hard drives if necessary.

Thanks

The answer is simple, in "Disk Management" right click on the C drive (the one you want as the system or "active") and set it to the active drive. That should solve the problem.