Outlook 2003 and using Word 2003 as email editor

I just installed a new Exchange 2003 server and used the install wizard to
configure each machine to upgrade Outlook from 2000 to 2003. We have used
Word 2000 in the past as the email editor program and it worked fine however,
we now have upgraded to Word 2003 as well. I have had many complaints from
users saying that when they go into their email and go under TOOLS, OPTIONS,
MAIL FORMAT tab, you cannot select "Use Microsoft Office Word 2003 to edit
email messages" or "Use Microsoft Office Word 2003 to read Text e-mail
messages" in all cases the two check boxes are grayed out. I do not have
Office installed on the Exchange server as each machine has its own copy of
Word 2003 on the local pc. If someone could please explain to me why these
boxes are grayed out I would greatly appreciate it. Thank you!!