1. A navigation system with switchable multi-language operating interfaces, comprising: a storage unit for storing installation programs and audio databases of the multi-language operating interfaces; a Basic Input/Output System (BIOS) for actuating the navigation system during a boot up thereof and controlling to display a selection interface of settings; a setup module for receiving a user selection from the selection interface; an installation module for loading and installing the corresponding installation program of the multi-language operating interface from the storage unit in accordance with the user selection; and a memory module for storing the installed multi-language operating interfaces, wherein the navigation system is configured such that once the multi-language operating interfaces are installed, there is no need to make a language selection when being warm-booted so that a language is switchable to a desired language without re-cold-booting the navigation system.