How to set security level of Internet Explorer Zones

[t0nZ]

After I learned how to add sites to trusted sites zone of IE (7,8,9) thanks to this thread

now i want to change the security level of trusted sites from "custom" to "low".

I have found a ms$ article ( support.microsoft.com/kb/182569 ) but it seems I have to change every single value... is it possible ?

Any ideas ? thanks.