Patent ID: 7774795

Claim:
A printer configured to receive print information from an information processing apparatus connected to said printer via an interface and to perform print processing based on the print information and comprising: detecting means for detecting whether or not an optional device is attached to said printer; selecting means for selecting, in accordance with a detection result of said detecting means, first identification information related to the printer or second identification information representing data related to said optional device; and identification information output means for transferring, the identification information as selected by said selecting means to said information processing apparatus in response to a received request from the information processing apparatus, wherein said detecting means is configured to repeat detection as to whether or not an optional device is attached to said printer at predetermined intervals after power on, wherein said selecting means selects the first identification information related to the printer if said detecting means does not detect the optional device or selects the second identification information representing data related to said optional device if said detecting means detected the optional device, and wherein the identification information selected by said selecting means and transferred to said information processing apparatus is used by the information processing apparatus to select a device driver.