Hi Bugs,
What you are missing is called the Worksheet Menu Bar. This particular bar cannot be inadvertently closed, so chances are it is just "misplaced" elsewhere on the screen. It is easy to accidentally move it somewhere else because all the toolbars can be moved from their default positions with a simple click and drag. It is possible you have even dragged the toobar outside of the Excel process window so that it does not appear to be attached to Excel. In addition it is also easy to make it change shape so that the menu items are arranged vertically rather than horizontally, or laid out in matrix form like a table. So check for the toolbar even outside the Excel window, and also check all the boundaries of the Excel process window. Once you find it simply click on it somewhere that does not activate one of its menu items and drag it back to the top left corner of the Excel process window.