A snipping tool picture of your Disk Management window attached might help, but as far as I can tell, the boot partition is normally C:. I think it then alternaltes between drives, although not sure. When you throw in DVD drives, removable storage, and the fact you might have changed the primary hard drive in the bios, it gets really hard to keep track of. If you are installing an OS, you need to know for sure where it is going, so I never make two partitions the same size.
Disk 0 in Disk Management is normally the lower SATA connector, but that does not mean it is the primary drive.
If you are getting ready to install and need any help, let us know ahead of time, it might head off problems later.