My Book

WD External Drives External Drives for PC
2

Hi and welcome, basically the biggest diference is the supported software for both. 

My Book

http://support.wd.com/product/download.asp?groupid=132&lang=en

My Book/My Book Essential (USB 3.0)

http://support.wd.com/product/download.asp?groupid=125&lang=en

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