Password Protection on My Book Essential 2TB

hey i have a 2 TB My Book Essential my question is

do you know the 256bit encription on the drive where you can’t access files unless you put your password in ???

well my question is this

can i apply that 256 encryption to a single folder ?? ie

im using mine for work backup and files and dvd rips and my brother wants to copy some of my rips but i dont want him to mess with other files so id like to just password protect a single folder

any easy way of doing this without installing software ??? my ideal thing would be

plug in drive > enter password > access external drive > double click " said folder " > enter password ???