Stumbled upon this app when searching for a windows based utility to change AAM level in WD HDDs other than HD tune 
What is Notebook Hardware Control (NHC)
With Notebook Hardware Control you can easily control the hardware components of your Notebook
Notebook Hardware Control helps you to:
- control the hardware and system power management
- customize the notebook (open source ACPI Control System)
- prolong the battery lifetime
- cool down the system and reduce power consumption
- monitor the hardware to avoid system failure
- make your notebook quiet
Actually you can use it for your desktop/download rigs as well. A very good software.
Here is the link
Notebook Hardware Control (NHC) - Homepage, Downloads, Help, Docu, FAQ, News - www.pbus-167.com
Google to get the pro edition 