r_server.exe is a part of a remote administrator application that allows a user to work on one or more remote computers. The application contains features such as File Transfer, NT security and Telnet.
Non-system processes like r_server.exe originate from software you installed on your system. Since most applications store data in your system's registry, it is likely that your registry has suffered fragmentation and accumulated invalid entries which can affect your PC's performance. It is recommended that you check your registry to identify slowdown issues