Hi,
Generally the Worksheet Menu can't be hidden, but if its just out of view
the second method below will expose it. Make sure Excel is Maximized.
First see if you can right click anywhere where the toolbars were and choose
Customize if you get the shortcut menu. If that works go to the first tab,
Toolbars, and turn on various checkboxes.
Second try pressing Alt+V, T, C. If this works you will be in the Customize
dialog box as above. Turn on various toolbar, partiularly the Worksheet Menu
Bar.
If none of these work you may want to re-install Excel.