Remote desktop connection problem in Server 2003.

When I am trying to connect remotely to domain controller with Windows Server 2003, it fails to connect and there is an error message displayed which says ‘Because of the network problem or it is not enabled to connect the client to remote server, it cannot be able to connect’. I cannot connect to my two virtual servers and also to another server which has connected to that server. It is also possible to get into VMware and able to view the domain controller. I have doubt that somebody changed the group policies. If anybody knows the solution to this problem, please help me. I will be thankful for all your help.
