Many users have reported losing commands from their menu bar. Try these
fixes (in order):
1. Open Tools | Customize. On the Toolbars tab, select Menu Bar and press
Reset. (Since you can't open the Customize dialog from the missing Tools
menu, double-click on an empty area of any toolbar to open it, or
right-click on the Menu Bar or any toolbar and choose Customize).
2. If that doesn't work, switch to the Commands tab and select Built-in
Menus in the Categories list. In the Commands list, select the appropriate
menu and drag it to the menu bar.
3. If that doesn't work (or the problem recurs on restarting Word), see
http://www.mvps.org/word/FAQs/AppErrors/MissingMenusEtc.htm