My new Western Digital My Book External Hard Drive is continually hovering around the 50% usage of my CPU.

I have already Checked "Pause Backup until computer is idle." Before I did this, it took 40 seconds to move from the Library to the Develop model in Lightroom 4.

I have also unsuccessfully tried to update the firmware several times on the new Hard Drive, but keep getting the message to close all drives and try again. I close all drives (and temporarily disable my Anti Virus) - Task Manager is empty, but I still keep getting the same message.

Any ideas to speed things up and update the firmware? It's driving me mad.