Tip - A Quick Tip to make sure Adprep /ForestPrep for Windows Server 2008 has run successfully
Adprep /ForestPrep must be executed to introduce a Windows Server 2008 in an existing Windows 2000 or Windows 2003 domain environment. This will show you how to make sure that it has run successfully.
Read more here...
http://www.windowsnetworking.com/kbase/WindowsTips/WindowsServer2008/AdminTips/ActiveDirectory/AQuickTiptomakesureAdprepForestPrepforWindowsServer2008hasrunsuccessfully.html