The feature described in this Help topic is only available if support for Japanese is enabled through Microsoft Office Language Settings.
You must also be using a Japanese Input Method Editor (IME) (IME: A program that enters East Asian text (Traditional Chinese, Simplified Chinese, Japanese, or Korean) into programs by converting keystrokes into complex East Asian characters. The IME is treated as an alternate type of keyboard layout.).
To set IME options, click Options on the Tools menu, and then click the Edit tab.
IME Control Active
Automatically turns the Japanese Input Method Editor on or off when the application is turned on or off. This option is visible only if, in Microsoft Office Language Settings, you chose Japanese as the language that defines default behavior in Office programs.
Displays undetermined text in the same manner as text at the insertion point, with word-wrapping as necessary.
Undetermined String Colors
Changes the color of undetermined text in the Japanese Input Method Editor. This option is only available with IME Standard, not Microsoft Natural Input.
Displays the Properties dialog box of the Microsoft Japanese IME in use, making it possible to change environment settings such as the input method and dictionary file settings.