[AUCTeX] No Math icon in emacs menu for windows7

[CaoJin]

Dear AUCTeX users:

I setuped emacs + auctex in windows7. My problem is that there is no 
icon of each math symbol from "Math" menu in emacs, as it shows in linux 
system when I open a .tex file.

Is there any way to make the math icon appear in windows?
I searched on google, but it seems no one talks about this.

Any suggestions would be appreciated!

Cao