…Overview…
 
How does Group Policy inheritance work? This is a question I am asked alot. It can be a complicated issue for a beginner or even for an experienced administrator if there are lots of policies involved. It’s also something that WILL crop up many times in the MCSE exams with various different scenarios and outcomes. There are pages and pages on the internet describing how the group policy inheritance works. Here I try and condense it as simply as possible to make an easy reference guide.

Basically the PC you are on will take its orders from the last policy applied to it. They are applied in the order below.

i.)   Local Policy.  
ii.)  Site Policy.
iii.)  Domain Policy.
iv.)  OU Policy.

So if we have a policy that says ”stand up” applied at Site Policy and not configured at either below then the computer will “stand up”.
If the policy is applied at Site level to ”stand up”, not configured at Domain and then another policy at OU level told to ”sit down”, the computer will ”sit down”.
However if the policy is applied at Site level to “stand up”, not configured at Domain and the “Stand Up” policy is disabled at OU level the computer will not stand up (It will not sit down either as this is a different policy.)
Get the picture?

(Yes, I know computers can’t stand up or sit down and there is no option for this in group policy.)

Block Policy Inheritance

There are exceptions to the above. When you apply a policy there is also an option for “Block policy inheritance” This means exactly as you would expect. If you apply a policy at OU level and select the “Block Policy inheritance” option then it will not inherit the policy from levels above it (Unless No Override is selected on the policy above.)

No Override

Another option when applying a group policy is “No Override”. When you select this option it means that policies below cannot override the rules selected in this policy.

If both No Override and Block Policy Inheritance are selected the No Override will win.