This will block any gpo that is being applied from a top level to the machine.
You can see my win2025 machine is in the infrastructure OU
Here you can see two GPO that will apply to that OU
Default Domain Policy and Windows 2025 Base Policy
Now we will check the win 2025 machine and see what is being applied
Run gpresult /H c:\report.html as a administrator on command prompt
Open the report
Click show all on the right > do a ctrl F and type applied you can see the two GPO’s being applied
Now lets block inheritance > in group policy management right click OU > Click block inheritance
You will notice it has a blue icon now
Now on the win 2025 machine type
Run gpupdate /force on command prompt as a administrator
Double click the report
You will notice now that that GPO from the top level is Denied now
All done enjoy