One of the Settings in Options Trust Center Settings is Grayed out

Hi,
Outlook is office product, I am sure one of you genius will be able to help me.
I been googling for past 1 day and no help yet
please help me with this
please look at attached image, I want to change this settting but doesn't allow me to change it. it is grayed out

6-28-2012 8-02-55 AM.jpg

home comp, but never mind, I was finally able to figure it out.
it is windows 7 and it is office 2010
so i have to run as administrator in order to change that setting
(run outlook as administrator from folder C:\Program Files\Microsoft Office\Office14 )
credit goes to this site
http://www.slipstick.com/developer/c...ccess-options/

Thanks