i think that you can run (as root) 'fdisk /dev/your drive (i.e sda, hda...). now you can delete all partitions with d option. press m for help
to see which options you have. after pressing 'd' you can chose which partition you want to delete. after deleting of all patitions you can now create new one.
if you want to have windows and linux you can create two partitons. pres 'n' for new partiton, then 'p' for primary, chose partition number and take default option for first cylinder. you can now chose how big should be your first partition. for example if you have 60 GB you can take 30 for win so that you type +30000M. now type n for new again for new partitions. i think you can now chose p or l (logical), but let's say that you are going to chose p, press p and now chose two times default for first and last cylinder.
NOW press t to change a partition's system id. chose partition 1 and then 7 if you want to format partition with ntfs. now press t again, 2 for second partition and than 83 for linux partitions. ok, now w for write partition table to disc and now try to install windows. while you are installing fedora you have option to install it on existing linux partition. chose that and install grub to mbr. don't forget to add windows to grub you'll be asked for that. hope this helps.