My wd my book Essential 2.0 is not recognized my my pc but recognized in device management

having a big issue with my wd my book Essential 2.0 it wont reconize on my windows 7 acer ax1900 -e4102 it did up to 3 weeks ago had it for over a year so it is out of warenty have all my important files on there before it went missing off my pc it was almost at full capasity so i was trying to delete and ove files to my main drive now i can find in in device mangment and it was not reconizeable in disk mangment but now i have a drive 1 but cant change a drive letter or even initlize it now i dont know what to do can someone please help me

Do not initialize if you want to restore the files

look for data recovery software online 

now its not recognized on disk magment ethier :confused: i cant find it anywhere on the computer 

Try a different cable or different computer

make sure the drive is connected to the wall outlet