Someone asked me if you could prevent admins from accidentally deleting OUs in Active Directory as the consequences of doing so could be very bad indeed. The answer of course is that No, you can't prevent admins from doing anything because they're admins! You need to train your admins properly and ensure you hire people who are careful and responsible.
However, one small but very nice feature of Active Directory in Windows Server 2008 (formerly called Longhorn) is that when you try and delete an OU you are prompted with an Are You Sure warning message. For more information about Active Directory in Windows Server 2008, see my book Introducing Windows Server 2008.
Mitch Tulloch is lead author for the Windows Vista Resource Kit from Microsoft Press, which is THE book for IT pros who want to deploy, maintain and support Windows Vista in mid- and large-sized network environments. Mitch is also the author of Introducing Windows Server 2008, the first book from Microsoft Press about the exciting new server platform. For more information on these and other books written by Mitch, see www.mtit.com.