Windows Server 2008 has a new feature to protect OU from accidental deletion.
if you try to delete an OU which was marked with the special protection option you will get the following error message when trying to delete the object:
“You do not have sufficient privileges to delete OUNAME, or this object is protected from accidental deletion”
In order to disable the object protection and delete the object we need to follow the steps below:
enable Advanced Features in Active Directory Users and Computers (go to view and tick advanced feature)
Then Right click on the Object and go to the security tab.
Un tick the explicit Deny permission set for Everyone.