Locked external drive and no place to enter a password

A few days ago I noticed My Book Essential external hard drive was flashing the little security lock on the front. I did not set a password nor have I ever set any security options on this drive.

I then realized I am no longer able to put files onto the hard drive or create new folders. I am however able to take files off the hard drive and I can read the files on the drive such as movies, pictures, etc. So I am not totally unable to use the drive but I do not have full access to it. 

I checked some solutions on how to fix this problem but I cannot get to a page to even enter a password like is shown in the My Book Essential user manual. I am not sure how to fix this problem without even the option of entering a password/setting a new one. Any help would be greatly appreciated. I really do not want to wipe the drive as I have over 800 gb on it. Thanks very much.

Hello Mate,

It seems to me you will need to backup your drive and then follow the WD failed to login steps below :