Half the time that doesn't really delete the partition and you get 2 installations of the OS.
Been there, done that numerous times.
An FDISK floppy will utterly, absolutely "nuke" it....:)
Uhm, if you delete the partition, it's gone. I've installed XP hundreds of times. Not once, EVER has a deleted partition hung around. Certainly if you don't delete it, you can have two installations listed. If you delete the partition it's gone. Period. End of story. No ifs, ands or buts. You also can't create an NTFS partition with Fdisk.
You have to hit the L key to delete a listed partition. If you didn't do that, certainly it'll still be there.