Methods and apparatus are provided for externally managing control target devices such as computer systems, cameras, recorders, etc., in an effective and secure manner. In particular examples, an external desktop agent is connected to a computer system. Remote desktop agent software need not be installed on the computer system. The external desktop agent receives commands such as keyboard and mouse commands from a control computer over a mechanism such as a bi-directional network. To provide security, the external desktop agent does not directly connect to the computer system over an interface such as universal serial bus (USB) but instead provides a PS/2 interface that connects to the computer system through a standard PS/2 to USB adapter. PS/2 does not allow bi-directional command signaling and does not provide file level access to potentially sensitive computer system data.