Call CreateRemoteComObject and use the name of the computer and the GUID you are trying to connect to. If it returns an error, this indicates a server problem, otherwise a client problem.

?

const
  MyGUID = '{444...   }';  //Whatever the guid is...
var
  Unk: IUnknown;
  Disp: IDispatch;
begin
  { Make sure this line works correctly }
  Unk := CreateRemoteComObject('server ', 
    StringToGUID(MyGUID));
  { If it does, then cast it to a IDispatch }
  Disp := Unk as IDispatch;
end;
?