A duplicate setting prevention system for an image processing apparatus includes a setting file, a set of history information, a determination unit, a setting unit, a prohibiting unit, and a history information recording unit. The setting file is stored in a removable memory removably mounted on an image processing apparatus and is for setting the image processing apparatus. The set of history information is stored in the removable memory and indicates that the image processing apparatus has been set based on the setting file. When the removable memory is mounted on the image processing apparatus, the determination unit reads out the history information set and determines that a setting has been performed to the image processing apparatus based on the setting file. The setting unit performs the setting to the image processing apparatus based on the setting file. The prohibiting unit prohibits the setting unit from performing the setting to the image processing apparatus when the determination unit determines that the setting has been performed to the image processing apparatus based on the setting file. The history information recording unit records, in the history information set of the removable memory, that the setting is performed to the image processing apparatus after the setting unit has completed the setting based on the setting file.