Menu bar does not show on screen?

I'll assume your profile is wrong (10.4.7?) and you are using Lion in full screen mode. If so click the double arrows in the menu bar which should appeare if you mouse into the menu bar area.

If that isn't the case then are you zoomed in? Contol + fingler drag on mouse (or scroll wheel) zooms in or out (see Mouse preferences, Screen Zoom, look at the little movie).

Hi..

Double click the title bar of whatever app you are runing. The bar at the very top of the window.

Control + Command + F will "Exit Full Screen"...