Unable to Log in to WD Smart Ware to Access Files

I have been using the WD My Book Essential 3TB since December or January with no real problems. But a few months ago, I unplugged and replugged either the power cord or USB cord.  Since then, I have been unable to access the icon to log in.  I have updated the driver, and I have unplugged & re-plugged both the power cord AND the USB cord.  I have a Windows 7 operating system.  When I click start and go to My computer, the WD Smart Ware icon used to be visible.  I would then be prompted to enter my password, and then I could access my data.  Now the Smart Ware icon is no longer visible.  What do I do now?

Try the steps provided on the following link:

WD external drive is not assigned a drive letter by Windows or Mac OSX and data on the drive is inaccessible

http://wdc.custhelp.com/app/answers/detail/a_id/1164