Go to Tools | Customize. On the Commands Tab, look in the Insert Category. If
it's not in there, look in the All Commands Category. I'm using Word 2003,
and it's in the Insert category.
Look for a button named Equation Editor. then, drag it up to the Toolbar of
your choice.
Watch the bottom right of the mouse pointer as you drag. When the X turns
into a + you can let go of the button and it will go onto the Toolbar.
tj
