The Task Bar has possibly been dragged down to the bottom of the screen. Move the mouse pointer to the bottom of the screen. Does it change from a pointer into a double headed vertical arrow? If so, press and hold the left mouse button and drag the Task Bar up to its original height.
If the above does not apply, press the alt key and then the s key om your keyboard to get your start menu up. Try start/ run/sfc, or sfc /scannow, not sure which it is as I don't have win me.You'll probably need the win me disc in the drive. Also I believe