Word does offer this feature, but it calls them "nonbreaking" spaces. To type a nonbreaking space, press Ctrl+Shift+Spacebar. If the key combination slips your mind, choose Insert » Symbol, click the Special Characters tab, and look for the "Nonbreaking Space" item.
Word also offers nonbreaking hyphens, which you can insert by pressing Ctrl+_ (that's Ctrl and the underscore key).
Nonbreaking spaces appear as normal spaces unless you display all punctuation marks (click the Show/Hide button on the Standard toolbar) or display spaces (choose Tools » Options, click the View tab, and check the Spaces box). Spaces then appear as dots, and nonbreaking spaces appear as degree symbols (see Figure 3-9).
Figure 3-9. Use nonbreaking or "hard" spaces to keep words together. Nonbreaking spaces appear as degree symbols when you have spaces displayed.