Laura,
Please take note that this is a 64-bit Operating Systems newsgroup and that
your question is Office related.
Anyway, in my Spanish Office 2003 at work the answer to your question would
be:
Click Tools, Customize.
Click on the Commands tab, click on Insert (left pane).
Choose Equation Editior (right pane), and drag it to the menu bar.
That should do it.

Carlos
"Laura C" wrote:
> Hello,
>
> I am having difficulty installing equation editor on my toolbar in Word. I
> can see it if I click on Insert and then Object and then go to equation
> editor, but how do I get it as an icon on my toolbar?
>
> Thank you.