I've locked myself out of group policies a couple of times. When this happens to you, you can gain access again running the following command:
dsacls.exe "CN={GUID},CN=Policies,CN=System,DC=local" /R "Authenticated users"© GeekLabInfo Use dsacls to gain access to active directory policies is a post from GeekLab.info. You are free to copy materials from GeekLab.info, but you are required to link back to http://www.geeklab.info