This screen appears if "assisted" partitioning was chosen on the "Disk Configuration" screen.
You will be prompted to select a disk to partition:
Select a disk to wipe out and partition: [hda] hda 1000 MB >
Choose one that suits you, or go with the default.
If the disk designation you entered is valid, you will see the next screen in the 'assisted' partition configuration series "Configuring: <the disk you choose>".