Pep

How to make Microsoft Security Essentials check for updates more often (Download Squad)

Oct 27th 2009 5:00PM When selecting the "Full Control" check-it, select too the check-it in the bottom "Apply these permissions to objects within ..." in order to make that all subkeys under this category get the new security properties and then you will be able to change the value.

My opinion, whe you have done this... return the security to the previous state.