The RPC is for remote access to the COM model of your computer, checks encryption and security layers when attempt is made to access COM objects. If I was an administrator had thousands of machines to keep updated and running I would want to be able to fix and update things via the RPC.
Same goes for the new help which works via RPC, if you are not using help via Remote Desktop then just disallow it.
Some under worked overpaid people go to work and use their home computer via a Remote Desktop to play video games all day and of course post on bulleting boards.
RPC has limited functionality without the Remote Registry running and if your machine is a HOME version you may not have Remote Registry installed anyhow.