To "look into" or extract the contents of a .rar file, you will need specialized archival software: Orange Box (engine branch) - Valve Developer Community
: Settings that define how the interface interacts with the underlying game engine or Steam. GUI_Orange_Box.rar
While "GUI_Orange_Box.rar" does not appear to be a widely documented official software package, the naming convention suggests it is a (RAR) containing a Graphical User Interface (GUI) for a specific application or mod . To "look into" or extract the contents of a