Can you actually get on to the McAfee website? How's about the
www.symantec.com website? If you can't I'm sorry to say but you've probably got infected with a virus. They tend to disable certain elements and obstruct your ability to visit the very sites that can help you.
You can uninstall ie from your Control Panel in Windows.... then you can reinstall it again from the same place. It's the add/remove windows components that you need to look for
Personally, I would recommend you download and install
Firefox
Not only is it free - it's way better than IE, has fab plugins and addons and is totally customisable with tabbed browsing... keeps your taskbar uncluttered
