How can I use other FAT partition?

[Markus]

You seem to be using FAT12 on it. Try one of these:
/dev/hda5 /mnt/hda5 msdos noauto,users,exec,umask=000 0 0
/dev/hda5 /mnt/hda5 auto noauto,users,exec,umask=000 0 0
And if you want automounting do also what champagnemojo said.
Something fishy about the start and end sectors, are you sure there's any space on hda5?