You could try doing an ALT-T, then choose customise
from the drop down menu that appears. Click on the Toolbars
tab, and make sure the box beside the "menu bar" etc., is checked. Click on close, and see if that works.
See also this MS Knowledgebase article for other ways to restore your menu and toolbars:http://support.microsoft.com/kb/291484
Hope this will help,