You can permanently delete a GPO, which includes deleting all its settings and links.
NOTE:If you want to temporarily remove the GPO from the set of applied policies, you can remove the GPO links. This will have the same effect as deleting the GPO, without destroying the GPO.
To permanently delete a GPO from an OU:
Select the GPO you want to remove.
On the Action menu, click Delete.
NOTE:If you only want to remove the GPO link, select the Remove the Link from the list radio button.
If you want to permanently delete the GPO and related links, select the Remove the Link and delete the GPO permanently radio button.
Click OK.