I am using OpManager MSP 6005, and have one Windows 2003 R2 server that I can not add Windows services for monitoring. I keep getting "The RPC server is unavailable" error. I checked that RPC and WMI services are running and ports 445 and 135 are not blocked. Also the account and password are correct. Several other servers on the same probe are working just fine. How can I fix this problem ?.