Windows Server 2003 introduces the ability to restore deleted
("tombstoned") objects. This simple command-line utility enumerates the
deleted objects in a domain and gives you the option of restoring each
one. Source code is based on sample code in the Microsoft Platform SDK.
This MS KB article describes the use of AdRestore:
Learn how to troubleshoot AD DS service failures or degraded performance. Learn how to recover deleted security objects and the AD DS database, and how to troubleshoot hybrid authentication issues.