1. A method for adjusting a character setting of an input device, wherein the input device comprises a plurality of input components for entering a plurality of characters; the plurality of input components correspond to the plurality of characters respectively according to the character setting; and the method comprising: (a) setting a corresponding relation between the plurality of input components and the plurality of characters respectively according to a default character setting; (b) performing a character setting conversion to convert the default character setting into a specific character setting, wherein each time the default character setting is converted into the specific character setting, the corresponding relation under a currently converted specific character setting is different from the corresponding relation under a previously converted specific character setting; (c) resetting the corresponding relation between the plurality of input components and the plurality of characters respectively according to the specific character setting, wherein the plurality of input components corresponding to the plurality of characters under the default character setting are assigned to the same plurality of characters under the specific character setting which is different from the default character setting, and at least one of the input components corresponds to a first character before the character setting conversion is performed and corresponds to a second character different from the first character after the character setting conversion is performed; and (d) displaying the specific character setting, wherein the specific character setting includes the corresponding relation between the plurality of input components and the plurality of characters.