External HDD won`t shut down

[speednfs]

When I shut down my computer normal my external HDD WD 320 GB doesn`t shut down. I hear HDD spin sound and click sound every apx 5 seconds. When i start up my computer HDD is spining normal and work usual just he was working with no problems.
What I need to do to my HDD shut down when i shut down my PC?

Thanks for help and sorry for bad english...

 

[foscooter]

Unplug it.

Your motherboard might have one of those USB always on features, to charge devices even when the PC itself is off. See if you can disable this in your BIOS.