Less Usable space in 1TB WD My Passport

WD External and Portable SSD Portable SSD
1

I bought a 1TB  WD My Passport and when I connected I had 931.5 GB of usable space 

Due to some reasons I had to partition it into 4 drives. On partionng into 

  1. 300GB  - I got 299 GB usable space .

  2. 300GB  - I got 299 GB usable space .

  3. 330GB  - I got 229 GB usable space .

4. I could not make the remaining 1.5 GB as separate Drive ,I am not able to use it,it is labelled as LOGICAL DRIVE .

Now I have only 927 GB of usable space.

 

Pls help me in making the four partions and can you help about this loss in usable free space.

Pls Explain about Logical Drive.

thanks … Reply soon  . . … . … 

2

It’s a Windows thing a 1 T drive is about 930 gig when formatted http://hardforum.com/showthread.php?t=1347640 

Joe