Just be careful when you mention the C: and D: drives, those are considered to be Windows drive letters. In Linux they are referred to as /dev/hda1 (your "C" drive), /dev/hdb1 (your "D" drive) , /dev/hdc1 (either your E drive or CDROM)
Of course these associations are just an example. Don't quote me on how your system was installed, since I don't have that info..
I still stand by my recommendation for burning a copy of Mandrake Move and running that BEFORE installing Mandrake on your computer [for an extreme
]
That way, you get a feel for what you are doing first and you don't accidentally erase your Windows files.