Howdy ... firstly I know Im not Larry but I posted the following some time ago which covers your question. Enjoy:
Have solved the problem with all iMac 27" HDD rumble / clicking!!!!!
By default ... the AAM is disabled on ALL HDD's (Seagate and WD) except one specific model.
Its an easy process for all Intel based machines (iMac's).
Simply make a BartPE BOOT CD. Here is the link:
http://www.nu2.nu/pebuilder/
You need to use an XP machine or VMware to make the boot CD using files from a XP OS CD OR from the XP machine you are making the CD with using the BartPE builder.
Thats the hard part
OK now get a USB stick and put the following file winaam.exe onto it (make sure you use a FAT32 or NTFS format on the stick) you get it from
http://www.withopf.com/tools/aam/
OK now your ready to kill the noise forever!
UNPLUG all USB devices except your USB stick.
RESTART your iMac and keep your finger on the OPTION (ALT) key during the bootup. This will give you a choice to boot from your HDD or CD. Choose the CD.
BOOT off the BartPE boot CD you made ... use a USB mouse because your bluetooth one is not supported in XP! You wont need a keyboard.
Now wait! Get a coffee! Booting from CD takes a while!
Finally you will have a windows XP type of desktop. Click on the START button and find the file manager. Open your USB stick and double click on the winaam.exe file.
Now follow the instructions ... just click on CONTINUE and choose whatever option LOUD or SOFT you want and activate. Don't worry if the app returns an error saying not set. Just click ok and start the app again. You will see the change now the second time. To test you can click on the test button to hear the difference. Keep going back and forth you'll get the idea!
When your done and the last setting was the drive on quiet. Click on START and then RESTART. Unplug your USB mouse if you like and the iMac will restart with almost ZERO noise from the HDD.
It scared the willy out of me somewhat the first boot because I was so used to hearing the drive click up etc ... now silence!!! Peace and fan noise
Good luck.
Seriously, this works!!!!!!!!!
All the best!