I have been denied write access to my WD External Drive

How do I encrypt my WD drive.

This is the message I am receiving:

You have been denied write access to the unencrypted removable E:.

If you wish to write to E:, you must first encrypt it.

Do you want to encrypt E:?

When I click yes, I get the following message:

Starting encryption process…
Starting acquiring access…

An error occurred during encryption

The process cannot access the file because it is being used

Does anyone know how to fix this?  If I encrypt it, will it erase it the drive?  

I haven’t copied anything to it as of yet.  It is brand new. 

Can you please provide the model number for the drive you have and the firmware version?