If it is a USB Flash Drive, there is an Eject option when you right click on the drive... or say Stop the drive using the icon on the Task bar...
but what about an External hard drive? There seems to be no such option when right clicking on the drive?
(ah, i found that it can be done by "Safely Remove ..." on the tiny Task bar icon... but is there a way to right click on the drive and do it too?)
