You don't mention the purpose of the server (domain controller, file & print, application, etc).
The first thing that comes to mind is that the DNS configured on that server is not pointing to the AD DNS server (which may be itself).
Also, if you're running Exchange on a Domain Controller, shutdowns take a LOT longer. But not THAT long!
Pat Richard, MCSE(2) MCSA:Messaging, CNA(2)