ok we need to set you up with a boot disk with fdisk on it. the following link will download a boot disk maker. http://people.jyu.fi/~eejuviik/utils/boot622.exe
once youve made the boot disk, pop it in your computer and boot off it.
when the A:\> prompt comes up type in [fdisk]
when that opens up choose option 3 type  and hit enter\return.
choose option  [Delete Non-DOS Partition]
(dos partitions are FAT/FAT32 windows NT forward uses NTFS *lil info*)
select each partition and delete them one by one.
put in your OS disk and take out your floppy and reboot.
see if that comes up.