An image processing device having a software registration list protected by security software in which predetermined software is registered and a function to permit software registered in the software registration list to be executed, the device comprising: a mode switching unit configured to switch between a normal mode in which software unregistered in the software registration list is not permitted to be installed and an install mode in which the unregistered software is permitted to be installed; a software registration list invalidator configured to invalidate the software registration list by invalidating the function of the security software during the install mode; a software registerer configured to register, in the software registration list, software installed while the software registration list is invalidated; and a software registration list validator configured to validate the software registration list by enabling the function of the security software after the installed software is registered in the software registration list, wherein the mode switching unit comprises a dedicated account generator configured to generate an account dedicated to the install mode on a condition that authentication of a user is established, and to enable the user to change a setting of the security software or access the software to be installed; an install mode automatic logon function imparting unit configured to impart, to the dedicated account, an automatic logon function to the install mode; and an install mode automatic logon permitting unit configured to permit automatic logon to the install mode with the dedicated account to which the automatic logon function is imparted, and the automatic logon to the install mode with the dedicated account is performed after restart processing of the image processing device is performed to reflect settings for switching the normal mode to the install mode. a mode switching unit configured to switch between a normal mode in which software unregistered in the software registration list is not permitted to be installed and an install mode in which the unregistered software is permitted to be installed; a software registration list invalidator configured to invalidate the software registration list by invalidating the function of the security software during the install mode; a software registerer configured to register, in the software registration list, software installed while the software registration list is invalidated; and a software registration list validator configured to validate the software registration list by enabling the function of the security software after the installed software is registered in the software registration list, wherein the mode switching unit comprises a dedicated account generator configured to generate an account dedicated to the install mode on a condition that authentication of a user is established, and to enable the user to change a setting of the security software or access the software to be installed; an install mode automatic logon function imparting unit configured to impart, to the dedicated account, an automatic logon function to the install mode; and an install mode automatic logon permitting unit configured to permit automatic logon to the install mode with the dedicated account to which the automatic logon function is imparted, and a dedicated account generator configured to generate an account dedicated to the install mode on a condition that authentication of a user is established, and to enable the user to change a setting of the security software or access the software to be installed; an install mode automatic logon function imparting unit configured to impart, to the dedicated account, an automatic logon function to the install mode; and an install mode automatic logon permitting unit configured to permit automatic logon to the install mode with the dedicated account to which the automatic logon function is imparted, and the automatic logon to the install mode with the dedicated account is performed after restart processing of the image processing device is performed to reflect settings for switching the normal mode to the install mode.