My Book Essential Edition 2.0 Suddenly not recognized

WD External Drives External Drives for PC
1

i bought a My Book Essential Edition 2.0 harddrive but after 4 months .Suddenly one day it’s not recognize to my computer .i don’t know what to do?i hope somebody will help me

my external harddrive model was WDH1U10000PN

2

my most of the work in that harddrive some help me