It does show a C drive and a D drive, but the D drive is a partition designated as a restore partition for windoze XP. I don't think it would be a good idea to mess with that partition. Another partition would have to be made up by reducing the NTFS partition, and creating a new Fat32 partition.
I am also curious as I do not want to mess up a new puter while I explore Linux as a Debian install. Or any distro install for that matter, as they all handle differently. I too would like to create a 10 gig area to learn Linux
On my old puter ( now dead mobo ) I did a HDD install on a spare HDD. I built that machine myself, and I had a very minimal licenced 98SE disc for it ( minimal content-full licence ), but I have never re-partitioned a drive with a working and valuable OS on it.