Alt will give you access to the bar, but only access, it's not 'actually' there. However, as it gives you access to the entire bar, maybe you can check all your settings there and figure out what happened?
When you hit alt, it brings up the bar and underlines a letter for each menu... f for file, e for edit, v for view.
While it's not there now... at least you can get to it!
Again, good luck! I know how irritating it can be to not be able to get a computer (that's supposed to be intuitive to use!) to cooperate sometimes!