Its in there already - look in programs->accessories.
If you (with no start menu open) right-click on the start menu and choose
open, you can browse through your start menu and move things around as you
wish.
Alternatively, get yourself to "start->programs->accessories" and find
'Windows Explorer', then right-click it and choose "send to->desktop". Then
you will find a shortcut to it on your desktop, which you can drag to your
quick launch bar, or wherever you want.