Hi I notice that when i open the EMC (E2K7), this error will be register in the Event Viewer. Process mmc.exe (PID=1812). An remote procedure call (RPC) request to the Microsoft Exchange Active Directory Topology service failed with error 1753 (Error 6d9 from HrGetServersForRole). Make sure that the Remote Procedure Call (RPC) service is running. In addition, make sure that the network ports that are used by RPC are not blocked by a firewall. Can someone assist me on how to resolve this issue.

Check availability & configof DC/GC & DNSon both exchange servers and DC's use DCDIAG & repadmin to check the health of your network / AD servers Make sure no firewalls are restricting any of the ports required to communicate between the servers

Also try logging onto the machine with another administrative account, delete the profile of the administrative account which you normally use from System Properties > Profiles, then restart & log back in using the origional Admin Accnt.