Word 2007 “Cannot use this feature without credentials” message

Whenever I try to protect or unprotect a document I am prompted to install a free version of Microsoft’s Information Rights Management software. If I opt out of doing the download it then gives me a message, “Cannot use this feature without credentials”. I have googled a solution to this problem but I’m not getting anywhere with it. Does anyone have a solution? I’m running Windows XP and Office 2007.