Disclosed is a computer system including a computer body operated according to a predetermined operating system, and a display device having a display section for receiving a video signal from the computer body to display images on the screen thereof in response to the received video signal. The computer body includes a language information-providing section adapted to provide the display device with information about the kind of language used in the operating system. The display device includes an OSD generating section adapted to generate an OSD for setting a display environment of the display device, a memory adapted to store a plurality of languages that can be used in the OSD therein and to store the language information received from the computer body, and an OSD control section adapted to control the OSD generating section to display the OSD on the display section by means of the same language as that used in the operating system in accordance with language information.