Want to use MyBook Essential drive formatted in NTFS in Mac OS-x as well as Windows 7

WD External Drives External Drives for PC
2

I don’t know much about Macs. Drives for Windows that are 2T and under are formatted NTFS MRB above 2T They are NTFS GPT. Does your Mac recognize drives larger than 2T? To write to a NTFS drive from a Mac you will need something like NTFS-3G http://mac-free.com/download/NTFS-3G.html

Joe