Question : Using a security group to deny access to default domain policy

I have automatic updates configured in our default domain policy and i'd like to exclude our production servers from it.  I set up a security group and added all the computer accounts for the servers I want excluded.  Then I added that security group to the group policy and checked deny apply policy.  When I doa gpupdate and gpresult it still shows that it's applying the default domain policy.  on the other hand, if I add just a single machine account to the ACL of the default domain policy and check the deny apply group policy it works as expected.  when I run gpresult it shows that it's been blocked by the ACL.  

Why won't this work with a security group containing the machine accounts?

Answer : Using a security group to deny access to default domain policy

Hi shanna1017,

Group policies are applied to OUs and only affect Computer or User objects within the OU (or a child OU) - They are not applied to Security or Distro Groups.

You should create a seperate OU for your production servers to be placed in and then block inheritance of the default GPO to that OU.

Cheers!