Maybe this article could help HOWTO: Installing Fonts Sample http://support.installshield.com/kb/view.asp?pcode=ALL&articleid=Q106077.
You may search for more articles on InstallShield support site at http://support.installshield.com/kb/default.asp

>Hey!
>
>The kind of font includes true type font (*.ttf) and file fon (*.fon)
>
>The kind of file fon is fonts Vietnamese , and I would like change fonts system windows because Visual foxpro cannot support Unicode for Vietnamese.