From the following :
http://www.howtogeek.com/howto/windo...menu-in-vista/
Add "Take Ownership" to Explorer Right-Click Menu in Win 7 or Vista
Taking ownership of system files or folders in Windows 7 or Vista is not a simple task. Whether you use the GUI or the command line, it takes far too many steps.
Thankfully somebody created a registry hack that will give you a menu item for “Take Ownership” that will handle all the steps for you...
There is a link there for this "hack". I've used it myself when all else failed. Please do a registry backup before making any changes just in case.