SFC error 0x000006ba (RPC server unavailable)

I am Windows XP Pro SP3 installed in my system. However, when i am trying to run SFC /SCANNOW command i am getting below error message.

"Windows File Protection could not initiate a scan of protected system files.The specific error code is 0x000006ba [The RPC server is unavailable."

I don't know why i am getting that error message as RPC service is running.

I have found a Microsoft knowledge base article related to the same error for windows 2000. You can refer it and try out the resolution mentioned there for fixing this error.
Windows File Protection may not start