+ 0 Votes FSMO roles perhaps? Was this old server running a global catalog? ManiacMan Updated - 6 years ago Before you demote any Windows Server 2003 DCs', you always have to check if any operations master roles are running on it and if it's a global catalog server. If you're missing one of the 5 FSMO roles and the old DC has been since removed from the domain, you'll have to forcefully seize the missing role onto an existing domain controller. You also mention something about an application, which may or may not have been programmed to query the old server holding the global catalog role. Check with the developers to see if the application can be reconfigured to point at another DC with the global catalog role. + 0 Votes Agreed. Put a sniffer on the network and see what's going on robo_dev 6 years ago Something like Ethereal or Wireshark is free. I would look closely at user Browser proxy settings and also make sure something odd (like ISA) is not installed on the server. Are the users mapping shares to the server? Printers? I would run a tracert from some workstations to your ISPs DNS server with the server up, and then run the same tracert with the server offline. + 0 Votes humm... CG IT Updated - 6 years ago ICS? what's the workstations gateway and DNS information? If the server is just "a server" having it offline shouldn't affect workstations ability to get to the internet because they aren't using is as a "route out" nor use it to get information about network resources.