1TB My Book Essential not showing up on PS3

When I go into Windows Explorer and click on the drive it pulls up the folders that I’ve added to it (Picture Folder, and Video Folder) so I’m guessing they are in the root folder.  However,  when I formatted it to FAT32, I created a 250GB parition that I thought the folders were placed into.  Excuse my ignorance as I’m not very tech savvy.  Thanks!