Do you have any other antivirus installed in your computer?
Did you have in the past? Which one?
RPC error is generally related to other antivirus present or, at least, firewall blocking. Do you use a firewall? Which one?
Anyway, RPC error is most likely correct by this procedure:
Go to Control Panel > Add/Remove programs > avast! antivirus > Remove
Then choose Repair function in the pop up window (Repair).
Unfortunatelly, it does not help in your case 
If this does not help, can you uninstall / boot / install / boot again?
And what is it then? ???
What does it mean?