A window display system has a text acquisition section for acquiring text of an original window in a superimposed region; a text transmitter for transmitting to a predetermined server the acquired text, the coordinates of the superimposed region, and the coordinates of each part of the text; and a display processor for receiving a screen generated in the server, and displaying the screen in the overlapping window, wherein the server has a screen generator for determining whether a predetermined keyword is contained in the text received from the user terminal, extracting the keyword and the URL if the keyword is contained in the text, and generating and transmitting a screen in which a link to a URL is embedded in the position of a keyword contained in the text on the basis of the coordinates of the text received from the user terminal.