Just cruise over to the MS site and you can find out more.
rpcss - rpcss.exe - Process Information
Process File: rpcss or rpcss.exe
Process Name: Remote Procedure Call Services
rpcss.exe is an executable of Microsoft Windows Operating System. It is reponsible for Remote Procedure Call services on the local machine. These are public services available to the local network. This program is important for the stable and secure running of your computer and should not be terminated.