Not a Word question, but it's not an Outlook matter, either: it's
either a hardware thing or a Windows thing.
Perhaps you have a laptop that has a built-in keyboard for French etc.
In that case, it's selected with a key somewhere on the keyboard.
Otherwise, you have inadvertently switched to a different electronic
keyboard in Windows. You toggle/cycle through keyboards by pressing
LeftAlt-Shift. If this is what happens, and you know you'll never have
any use for the French (or whatever) keyboard, you can disable it from
your system via Start > Control Panel > Regional and Language Options.
(What you do after you get that far depends rather heavily on whether
you have Windows XP or Vista, but it should be _fairly_ clear how to
proceed from there.)