The interface relies on Internet Explorer to work so what version of Internet Explorer is installed? Open it and click Help/About and post the details.
Also what operating system and sevrice pack is this?
The version of IE I have installed is Beta 9.0.7930, which i think is the newest release. That's actually around the time I noticed the interface was missing. I am running Windows 7 ultimate 32-bit version. So if I uninstall IE9 and go back to the previous version, will I see the interface again?
Yes the McAfee interface is basically an IE page. It will eventually work OK once IE9 is final. It's just so much changes with betas that one minute it works and the next it doesn't so there isn't much point in the designers constantly trying to fix it, best to wait and see what's in the final version.