Hardware wd 1tb essential my book edition partition problem

[Zalda]

i have 2 partitions on my 1tb external hd, the w partition for my Wii isoz and the z partition for my other warez
i formatted my w partition on the wii with usb iso loader to wbfs, but when i got on the pc, wbfs manager 2.2.2 won't recognize the drive!
there's only one partition according to it, but there are 2!

 

[Zalda]

i really want to know how i can make my hd have 2 partitions, one for wii games and one for pc use