The My Book Essential comes formatted for Windows, you need to reformat it for Mac, then SmartWare should recognize it: How to partition and format a WD drive on Windows (7, Vista, XP) and Mac OSX
The My Book Essential comes formatted for Windows, you need to reformat it for Mac, then SmartWare should recognize it: How to partition and format a WD drive on Windows (7, Vista, XP) and Mac OSX