the manufacturer/vendor install restore/master cd that came with your computer to install windows? If so, that cd might have created the second harddrive (partition) by default because that's where it keeps its files in case you want to add/remove components or need to replace a corrupt file.
I have recently bought a new hard drive to replace the old one for my computer. I installed it and in the "My computer" window it shows that I have two hard drives installed when I really only have one. What does this mean? It shows that there are files stored on this "second" hard drive. Is there a way to delete this "fake" drive?