am trying to use boot camp on my Macbook and I keep getting this message when it tries to partition the hard drive:

"Back up the disk and use Disk Utility to format the disk as a single Mac OS Extended (Journaled) volume. Restore your information to the disk and try using Boot Camp Assistant again."

I read on another thread that this was because my hard drive is already partitioned? So I opened disk utility and I have these two drives:

Macintosh HD and "74.5 GB ST98823AS Media"

What is that second partition?? It says it is "read/write" and "GUID Partition table" at the bottom. it doesnt say that there are any files or available space on it. I have an 80 GB harddrive, which all shows up under the Macintosh HD section.