Have you tried to restart and put the CD in the drive? This is what I used to do fresh installs from where I work @ Scott City. Then, it will display the partitions, and you delete that partition.
A+ Core Hardware, Software Certified (May 13 2005)
the new beast...
AMD Athlon XP 3200+ Barton running at 2.16 Ghz.
GeForce MX 4000 (mainly takes the load off the main system)
Creative Labs Audigy 24-bit sound.
Some Case from tigerdirect
512 MB Ultra DDR RAM.
80GB Seagate HDD
LiteOn CD-RW / DVD ROM drive.
currently looking at a litescribe drive at staples, due to its ability to label the CD shortly after being burned.