format hard drive

I have succesfully installed a new hard drive as new XP
boot disk.

The older (original boot disk) hard disk is now used as
the slave drive. How can I format this to remove the old
partitions?

In disk management it shows a small FAT partition as the
primary and the remainder as a NTFS partiton. I want to
make the whole disk into one NTFS partition. However, if
I right mouse click on the small FAT partiton it only
gives me the help option. How can I remove this FAT
partition and start a fresh and reformat the whole drive?

Thanks