Hit the Alt key to show the Menu bar, then open View > Toolbars and select Menu bar, so it has a check-mark.

Thank you ,thank you so much the alt key really works I GOT MY TOOL BARS BACK!

Thank you soooooo much. I was driving me crazy not knowing how to get the toolbar back...

I hit the Alt key and no Menu bar appeared. this happened after my computer updated. Now the top of the firefox google page bounces up and down and there is nowhere to get off the page except Ctrl Alt Delete and end firefox.