An image forming system comprising: an image forming apparatus (1, 1a) including an image forming part forming an image; and an external terminal communicably connected to the image forming apparatus, characterized in that the image forming system comprises: a database communicably connected to the image forming apparatus, the database configured to previously register the external terminal belonging to a group and log-in information of this external terminal in association with a user being a representative of the group, the image forming apparatus comprises: a user authenticating part configured to authenticate a user on the basis of authentication information peculiar to the user in installing operation of a driver of the image forming apparatus with regard to an external terminal communicably connected to the image forming apparatus; a terminal selecting part configured to select, when the user being the representative is authenticated by the user authenticating part, the external terminal belonging to the group, that is registered in association with the authenticated user, as an object terminal in the installing operation from the database; and an installation instructing part configured to establish remote access to the object terminal on the basis of the log-in information previously registered with regard to the object terminal selected by the terminal selecting part and to transmit installation instruction of automatic installation of the driver to the object terminal. an image forming apparatus (1, 1a) including an image forming part forming an image; and an external terminal communicably connected to the image forming apparatus, characterized in that the image forming system comprises: a database communicably connected to the image forming apparatus, the database configured to previously register the external terminal belonging to a group and log-in information of this external terminal in association with a user being a representative of the group, the image forming apparatus comprises: a user authenticating part configured to authenticate a user on the basis of authentication information peculiar to the user in installing operation of a driver of the image forming apparatus with regard to an external terminal communicably connected to the image forming apparatus; a terminal selecting part configured to select, when the user being the representative is authenticated by the user authenticating part, the external terminal belonging to the group, that is registered in association with the authenticated user, as an object terminal in the installing operation from the database; and an installation instructing part configured to establish remote access to the object terminal on the basis of the log-in information previously registered with regard to the object terminal selected by the terminal selecting part and to transmit installation instruction of automatic installation of the driver to the object terminal. a database communicably connected to the image forming apparatus, the database configured to previously register the external terminal belonging to a group and log-in information of this external terminal in association with a user being a representative of the group, the image forming apparatus comprises: a user authenticating part configured to authenticate a user on the basis of authentication information peculiar to the user in installing operation of a driver of the image forming apparatus with regard to an external terminal communicably connected to the image forming apparatus; a terminal selecting part configured to select, when the user being the representative is authenticated by the user authenticating part, the external terminal belonging to the group, that is registered in association with the authenticated user, as an object terminal in the installing operation from the database; and an installation instructing part configured to establish remote access to the object terminal on the basis of the log-in information previously registered with regard to the object terminal selected by the terminal selecting part and to transmit installation instruction of automatic installation of the driver to the object terminal. a user authenticating part configured to authenticate a user on the basis of authentication information peculiar to the user in installing operation of a driver of the image forming apparatus with regard to an external terminal communicably connected to the image forming apparatus; a terminal selecting part configured to select, when the user being the representative is authenticated by the user authenticating part, the external terminal belonging to the group, that is registered in association with the authenticated user, as an object terminal in the installing operation from the database; and an installation instructing part configured to establish remote access to the object terminal on the basis of the log-in information previously registered with regard to the object terminal selected by the terminal selecting part and to transmit installation instruction of automatic installation of the driver to the object terminal.