Hello,
This is because the " My book essentia" is a NTFS (windows) Drive and you are using a mac, in orde to use this drive you will have to format it to HFS (mac os extended journaled ) in a GUID partition,
Please follow the guide below on how to do this,
Format Guide (choose your OS first)
Also if you do not like that (annoying) software, you are able to disable it, if you do not want the software use the guide below on how to disable the virtual cd with smart ware
Please try this, it should work 
Greets
Random WD Fan
